diff --git a/tests/parallel_test/cases.task b/tests/parallel_test/cases.task
index 6e662a9a15a656882d531b67103cc354c7c8a33c..97858e5d712b825f0d4cfcd1ce42eea9076875e3 100644
--- a/tests/parallel_test/cases.task
+++ b/tests/parallel_test/cases.task
@@ -51,6 +51,16 @@
 ,,y,system-test,./pytest.sh python3 ./test.py -f 2-query/nestedQuery_math.py -Q 3
 ,,y,system-test,./pytest.sh python3 ./test.py -f 2-query/nestedQuery_time.py -Q 3
 ,,y,system-test,./pytest.sh python3 ./test.py -f 2-query/nestedQuery_26.py -Q 3
+,,y,system-test,./pytest.sh python3 ./test.py -f 2-query/select_null.py
+,,y,system-test,./pytest.sh python3 ./test.py -f 2-query/select_null.py -R
+,,y,system-test,./pytest.sh python3 ./test.py -f 2-query/select_null.py -Q 2
+,,y,system-test,./pytest.sh python3 ./test.py -f 2-query/select_null.py -Q 3
+,,y,system-test,./pytest.sh python3 ./test.py -f 2-query/select_null.py -Q 4
+,,y,system-test,./pytest.sh python3 ./test.py -f 2-query/slimit.py
+,,y,system-test,./pytest.sh python3 ./test.py -f 2-query/slimit.py -R
+,,y,system-test,./pytest.sh python3 ./test.py -f 2-query/slimit.py -Q 2
+,,y,system-test,./pytest.sh python3 ./test.py -f 2-query/slimit.py -Q 3
+,,y,system-test,./pytest.sh python3 ./test.py -f 2-query/slimit.py -Q 4
 
 ,,y,system-test,./pytest.sh python3 ./test.py -f 7-tmq/create_wrong_topic.py
 ,,y,system-test,./pytest.sh python3 ./test.py -f 7-tmq/dropDbR3ConflictTransaction.py -N 3
diff --git a/tests/system-test/1-insert/database_pre_suf.py b/tests/system-test/1-insert/database_pre_suf.py
index a6ff95ab3ffbea78350e6f7abccbcc8c53c572aa..2e993b9a405eab3ac76f0318fffaadd805808686 100755
--- a/tests/system-test/1-insert/database_pre_suf.py
+++ b/tests/system-test/1-insert/database_pre_suf.py
@@ -24,9 +24,7 @@ from util.dnodes import tdDnodes
 from util.dnodes import *
 
 class TDTestCase:
-    updatecfgDict = {'maxSQLLength':1048576,'debugFlag': 143 ,"cDebugFlag":143,"uDebugFlag":143 ,"rpcDebugFlag":143 , "tmrDebugFlag":143 , 
-    "jniDebugFlag":143 ,"simDebugFlag":143,"dDebugFlag":143, "dDebugFlag":143,"vDebugFlag":143,"mDebugFlag":143,"qDebugFlag":143,
-    "wDebugFlag":143,"sDebugFlag":143,"tsdbDebugFlag":143,"tqDebugFlag":143 ,"fsDebugFlag":143 ,"fnDebugFlag":143}
+    updatecfgDict = {'maxSQLLength':1048576,'debugFlag': 135}
     
     def init(self, conn, logSql, replicaVar=1):
         self.replicaVar = int(replicaVar)
@@ -39,7 +37,9 @@ class TDTestCase:
         
         self.db = "pre_suf"
 
-    def dropandcreateDB_random(self,database,n,vgroups,table_prefix,table_suffix,check_result):
+    def dropandcreateDB_random(self,database,n,vgroups,table_prefix,table_suffix,check_result_positive,check_result_negative):
+        #check_result_positive 检查前缀后缀是正数的，check_result_negative 检查前缀后缀是负数的(TS-3249)
+        tdLog.info(f"create start:n:{n},vgroups:{vgroups},table_prefix:{table_prefix},table_suffix:{table_suffix},check_result_positive:{check_result_positive},check_result_negative:{check_result_negative}") 
         ts = 1630000000000
         num_random = 100
         fake = Faker('zh_CN')
@@ -56,6 +56,7 @@ class TDTestCase:
                 q_int_null int , q_bigint_null bigint , q_smallint_null smallint , q_tinyint_null tinyint, q_float_null float , q_double_null double , q_bool_null bool , q_binary_null binary(20) , q_nchar_null nchar(20) , q_ts_null timestamp) \
                 tags(loc nchar(100) , t_int int , t_bigint bigint , t_smallint smallint , t_tinyint tinyint, t_bool bool , t_binary binary(100) , t_nchar nchar(100) ,t_float float , t_double double , t_ts timestamp);''')
         
+        #positive
         for i in range(10*n):
             tdSql.execute('''create table bj_%d (ts timestamp , q_int int , q_bigint bigint , q_smallint smallint , q_tinyint tinyint , q_float float , q_double double , q_bool bool , q_binary binary(100) , q_nchar nchar(100) , q_ts timestamp ) ;'''%i)
             tdSql.execute('''create table sh_%d (ts timestamp , q_int int , q_bigint bigint , q_smallint smallint , q_tinyint tinyint , q_float float , q_double double , q_bool bool , q_binary binary(100) , q_nchar nchar(100) , q_ts timestamp ) ;'''%i)
@@ -106,11 +107,60 @@ class TDTestCase:
                         fake.random_int(min=-32767, max=32767, step=1) , fake.random_int(min=-127, max=127, step=1) , 
                         fake.pystr() ,fake.pystr() ,fake.pyfloat(),fake.pyfloat(),fake.random_int(min=-2147483647, max=2147483647, step=1)))
 
-        
+        #negative
+        for i in range(10*n):
+            tdSql.execute('''create table bj_table_%d_r_negative (ts timestamp , q_int int , q_bigint bigint , q_smallint smallint , q_tinyint tinyint , q_float float , q_double double , q_bool bool , q_binary binary(100) , q_nchar nchar(100) , q_ts timestamp ) ;'''%i)
+            tdSql.execute('''create table sh_table_%d_r_negative (ts timestamp , q_int int , q_bigint bigint , q_smallint smallint , q_tinyint tinyint , q_float float , q_double double , q_bool bool , q_binary binary(100) , q_nchar nchar(100) , q_ts timestamp ) ;'''%i)
+            tdSql.execute('''create table hn_table_%d_r_negative \
+                    (ts timestamp , q_int int , q_bigint bigint , q_smallint smallint , q_tinyint tinyint , q_float float , q_double double , q_bool bool , q_binary binary(100) , q_nchar nchar(100) , q_ts timestamp , \
+                    q_binary1 binary(100) , q_nchar1 nchar(100) ,q_binary2 binary(100) , q_nchar2 nchar(100) ,q_binary3 binary(100) , q_nchar3 nchar(100) ,q_binary4 binary(100) , q_nchar4 nchar(100) ,\
+                    q_binary5 binary(100) , q_nchar5 nchar(100) ,q_binary6 binary(100) , q_nchar6 nchar(100) ,q_binary7 binary(100) , q_nchar7 nchar(100) ,q_binary8 binary(100) , q_nchar8 nchar(100) ,\
+                    q_int_null int , q_bigint_null bigint , q_smallint_null smallint , q_tinyint_null tinyint, q_float_null float , q_double_null double , q_bool_null bool , q_binary_null binary(20) , q_nchar_null nchar(20) , q_ts_null timestamp) ;'''%i)
+            
+            tdSql.execute('''create table bj_stable_1_%d_negative using stable_1 tags('bj_stable_1_%d', '%d' , '%d', '%d' , '%d' , 1 , 'binary1.%s' , 'nchar1.%s' , '%f', '%f' ,'%d') ;''' 
+                      %(i,i,fake.random_int(min=-2147483647, max=2147483647, step=1), fake.random_int(min=-9223372036854775807, max=9223372036854775807, step=1), 
+                        fake.random_int(min=-32767, max=32767, step=1) , fake.random_int(min=-127, max=127, step=1) , 
+                        fake.pystr() ,fake.pystr() ,fake.pyfloat(),fake.pyfloat(),fake.random_int(min=-2147483647, max=2147483647, step=1))) 
+            tdSql.execute('''create table sh_table_%d_a_negative using stable_1 tags('sh_a_table_1_%d', '%d' , '%d', '%d' , '%d' , 1 , 'binary1.%s' , 'nchar1.%s' , '%f', '%f' ,'%d') ;''' 
+                      %(i,i,fake.random_int(min=-2147483647, max=2147483647, step=1), fake.random_int(min=-9223372036854775807, max=9223372036854775807, step=1), 
+                        fake.random_int(min=-32767, max=32767, step=1) , fake.random_int(min=-127, max=127, step=1) , 
+                        fake.pystr() ,fake.pystr() ,fake.pyfloat(),fake.pyfloat(),fake.random_int(min=-2147483647, max=2147483647, step=1))) 
+            tdSql.execute('''create table sh_table_%d_b_negative using stable_1 tags('sh_b_table_1_%d', '%d' , '%d', '%d' , '%d' , 1 , 'binary1.%s' , 'nchar1.%s' , '%f', '%f' ,'%d') ;''' 
+                      %(i,i,fake.random_int(min=-2147483647, max=2147483647, step=1), fake.random_int(min=-9223372036854775807, max=9223372036854775807, step=1), 
+                        fake.random_int(min=-32767, max=32767, step=1) , fake.random_int(min=-127, max=127, step=1) , 
+                        fake.pystr() ,fake.pystr() ,fake.pyfloat(),fake.pyfloat(),fake.random_int(min=-2147483647, max=2147483647, step=1)))
+            tdSql.execute('''create table sh_table_%d_c_negative using stable_1 tags('sh_c_table_1_%d', '%d' , '%d', '%d' , '%d' , 1 , 'binary1.%s' , 'nchar1.%s' , '%f', '%f' ,'%d') ;''' 
+                      %(i,i,fake.random_int(min=-2147483647, max=2147483647, step=1), fake.random_int(min=-9223372036854775807, max=9223372036854775807, step=1), 
+                        fake.random_int(min=-32767, max=32767, step=1) , fake.random_int(min=-127, max=127, step=1) , 
+                        fake.pystr() ,fake.pystr() ,fake.pyfloat(),fake.pyfloat(),fake.random_int(min=-2147483647, max=2147483647, step=1)))
+            
+            tdSql.execute('''create table bj_table_%d_a_negative using stable_1 tags('bj_a_table_1_%d', '%d' , '%d', '%d' , '%d' , 1 , 'binary1.%s' , 'nchar1.%s' , '%f', '%f' ,'%d') ;''' 
+                      %(i,i,fake.random_int(min=-2147483647, max=2147483647, step=1), fake.random_int(min=-9223372036854775807, max=9223372036854775807, step=1), 
+                        fake.random_int(min=-32767, max=32767, step=1) , fake.random_int(min=-127, max=127, step=1) , 
+                        fake.pystr() ,fake.pystr() ,fake.pyfloat(),fake.pyfloat(),fake.random_int(min=-2147483647, max=2147483647, step=1))) 
+            tdSql.execute('''create table bj_table_%d_b_negative using stable_1 tags('bj_b_table_1_%d', '%d' , '%d', '%d' , '%d' , 1 , 'binary1.%s' , 'nchar1.%s' , '%f', '%f' ,'%d') ;''' 
+                      %(i,i,fake.random_int(min=-2147483647, max=2147483647, step=1), fake.random_int(min=-9223372036854775807, max=9223372036854775807, step=1), 
+                        fake.random_int(min=-32767, max=32767, step=1) , fake.random_int(min=-127, max=127, step=1) , 
+                        fake.pystr() ,fake.pystr() ,fake.pyfloat(),fake.pyfloat(),fake.random_int(min=-2147483647, max=2147483647, step=1)))
+            tdSql.execute('''create table bj_table_%d_c_negative using stable_1 tags('bj_c_table_1_%d', '%d' , '%d', '%d' , '%d' , 1 , 'binary1.%s' , 'nchar1.%s' , '%f', '%f' ,'%d') ;''' 
+                      %(i,i,fake.random_int(min=-2147483647, max=2147483647, step=1), fake.random_int(min=-9223372036854775807, max=9223372036854775807, step=1), 
+                        fake.random_int(min=-32767, max=32767, step=1) , fake.random_int(min=-127, max=127, step=1) , 
+                        fake.pystr() ,fake.pystr() ,fake.pyfloat(),fake.pyfloat(),fake.random_int(min=-2147483647, max=2147483647, step=1)))
+
+            
+            tdSql.execute('''create table tj_table_%d_a_negative using stable_2 tags('tj_a_table_2_%d', '%d' , '%d', '%d' , '%d' , 1 , 'binary1.%s' , 'nchar1.%s' , '%f', '%f' ,'%d') ;''' 
+                      %(i,i,fake.random_int(min=-2147483647, max=2147483647, step=1), fake.random_int(min=-9223372036854775807, max=9223372036854775807, step=1), 
+                        fake.random_int(min=-32767, max=32767, step=1) , fake.random_int(min=-127, max=127, step=1) , 
+                        fake.pystr() ,fake.pystr() ,fake.pyfloat(),fake.pyfloat(),fake.random_int(min=-2147483647, max=2147483647, step=1))) 
+            tdSql.execute('''create table tj_table_%d_b_negative using stable_2 tags('tj_b_table_2_%d', '%d' , '%d', '%d' , '%d' , 1 , 'binary1.%s' , 'nchar1.%s' , '%f', '%f' ,'%d') ;''' 
+                      %(i,i,fake.random_int(min=-2147483647, max=2147483647, step=1), fake.random_int(min=-9223372036854775807, max=9223372036854775807, step=1), 
+                        fake.random_int(min=-32767, max=32767, step=1) , fake.random_int(min=-127, max=127, step=1) , 
+                        fake.pystr() ,fake.pystr() ,fake.pyfloat(),fake.pyfloat(),fake.random_int(min=-2147483647, max=2147483647, step=1)))
+            
         # create stream
         tdSql.execute('''create stream current_stream trigger at_once IGNORE EXPIRED 0 into stream_max_stable_1 as select _wstart as startts, _wend as wend, max(q_int) as max_int, min(q_bigint) as min_int from stable_1 where ts is not null interval (5s);''')
         
-        # insert data
+        # insert data positive
         for i in range(num_random*n):        
             tdSql.execute('''insert into bj_stable_1_1  (ts , q_int , q_bigint , q_smallint , q_tinyint , q_float , q_double , q_bool , q_binary , q_nchar, q_ts,\
                         q_binary1 , q_nchar1 , q_binary2 , q_nchar2 , q_binary3 , q_nchar3 , q_binary4 , q_nchar4 , q_binary5 , q_nchar5 , q_binary6 , q_nchar6 , q_binary7 , q_nchar7, q_binary8 , q_nchar8) \
@@ -180,8 +230,60 @@ class TDTestCase:
                         fake.pyfloat() , fake.pyfloat() , fake.pystr() , fake.pystr() , ts + i, fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , 
                         fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr()))
 
+        # insert data negative
+        for i in range(num_random*n):        
+            tdSql.execute('''insert into bj_stable_1_1_negative  (ts , q_int , q_bigint , q_smallint , q_tinyint , q_float , q_double , q_bool , q_binary , q_nchar, q_ts,\
+                        q_binary1 , q_nchar1 , q_binary2 , q_nchar2 , q_binary3 , q_nchar3 , q_binary4 , q_nchar4 , q_binary5 , q_nchar5 , q_binary6 , q_nchar6 , q_binary7 , q_nchar7, q_binary8 , q_nchar8) \
+                        values(%d, %d, %d, %d, %d, %f, %f, 0, 'binary.%s', 'nchar.%s', %d, 'binary1.%s', 'nchar1.%s', 'binary2.%s', 'nchar2.%s', 'binary3.%s', 'nchar3.%s', \
+                        'binary4.%s', 'nchar4.%s', 'binary5.%s', 'nchar5.%s', 'binary6.%s', 'nchar6.%s', 'binary7.%s', 'nchar7.%s', 'binary8.%s', 'nchar8.%s') ;''' 
+                        % (ts + i*1000, fake.random_int(min=-2147483647, max=2147483647, step=1), 
+                        fake.random_int(min=-9223372036854775807, max=9223372036854775807, step=1), 
+                        fake.random_int(min=-32767, max=32767, step=1) , fake.random_int(min=-127, max=127, step=1) , 
+                        fake.pyfloat() , fake.pyfloat() , fake.pystr() , fake.pystr() , ts + i , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , 
+                        fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr()))
+
+            tdSql.execute('''insert into bj_stable_1_2_negative (ts , q_int , q_bigint , q_smallint , q_tinyint , q_float , q_double, q_bool , q_binary , q_nchar, q_ts,\
+                        q_binary1 , q_nchar1 , q_binary2 , q_nchar2 , q_binary3 , q_nchar3 , q_binary4 , q_nchar4 , q_binary5 , q_nchar5 , q_binary6 , q_nchar6 , q_binary7 , q_nchar7, q_binary8 , q_nchar8)\
+                        values(%d, %d, %d, %d, %d, %f, %f, 1, 'binary.%s', 'nchar.%s', %d, 'binary1.%s', 'nchar1.%s', 'binary2.%s', 'nchar2.%s', 'binary3.%s', 'nchar3.%s', \
+                        'binary4.%s', 'nchar4.%s', 'binary5.%s', 'nchar5.%s', 'binary6.%s', 'nchar6.%s', 'binary7.%s', 'nchar7.%s', 'binary8.%s', 'nchar8.%s') ;''' 
+                        % (ts + i*1000, fake.random_int(min=0, max=2147483647, step=1), 
+                        fake.random_int(min=0, max=9223372036854775807, step=1), 
+                        fake.random_int(min=0, max=32767, step=1) , fake.random_int(min=0, max=127, step=1) , 
+                        fake.pyfloat() , fake.pyfloat() , fake.pystr() , fake.pystr() , ts + i, fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , 
+                        fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr()))
+
+            tdSql.execute('''insert into bj_stable_1_3_negative (ts , q_int , q_bigint , q_smallint , q_tinyint , q_float , q_double, q_bool , q_binary , q_nchar, q_ts,\
+                        q_binary1 , q_nchar1 , q_binary2 , q_nchar2 , q_binary3 , q_nchar3 , q_binary4 , q_nchar4 , q_binary5 , q_nchar5 , q_binary6 , q_nchar6 , q_binary7 , q_nchar7, q_binary8 , q_nchar8) \
+                        values(%d, %d, %d, %d, %d, %f, %f, 0, 'binary.%s', 'nchar.%s', %d, 'binary1.%s', 'nchar1.%s', 'binary2.%s', 'nchar2.%s', 'binary3.%s', 'nchar3.%s', \
+                        'binary4.%s', 'nchar4.%s', 'binary5.%s', 'nchar5.%s', 'binary6.%s', 'nchar6.%s', 'binary7.%s', 'nchar7.%s', 'binary8.%s', 'nchar8.%s') ;''' 
+                        % (ts + i*1000, fake.random_int(min=-0, max=2147483647, step=1), 
+                        fake.random_int(min=-0, max=9223372036854775807, step=1), 
+                        fake.random_int(min=-0, max=32767, step=1) , fake.random_int(min=-0, max=127, step=1) , 
+                        fake.pyfloat() , fake.pyfloat() , fake.pystr() , fake.pystr() , ts + i, fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , 
+                        fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr()))
+
+            tdSql.execute('''insert into bj_stable_1_4_negative (ts , q_int , q_bigint , q_smallint , q_tinyint , q_float , q_double, q_bool , q_binary , q_nchar, q_ts,\
+                        q_binary1 , q_nchar1 , q_binary2 , q_nchar2 , q_binary3 , q_nchar3 , q_binary4 , q_nchar4 , q_binary5 , q_nchar5 , q_binary6 , q_nchar6 , q_binary7 , q_nchar7, q_binary8 , q_nchar8) \
+                        values(%d, %d, %d, %d, %d, %f, %f, 0, 'binary.%s', 'nchar.%s', %d, 'binary1.%s', 'nchar1.%s', 'binary2.%s', 'nchar2.%s', 'binary3.%s', 'nchar3.%s', \
+                        'binary4.%s', 'nchar4.%s', 'binary5.%s', 'nchar5.%s', 'binary6.%s', 'nchar6.%s', 'binary7.%s', 'nchar7.%s', 'binary8.%s', 'nchar8.%s') ;''' 
+                        % (ts + i*1000 +1, fake.random_int(min=-0, max=2147483647, step=1), 
+                        fake.random_int(min=-0, max=9223372036854775807, step=1), 
+                        fake.random_int(min=-0, max=32767, step=1) , fake.random_int(min=-0, max=127, step=1) , 
+                        fake.pyfloat() , fake.pyfloat() , fake.pystr() , fake.pystr() , ts + i, fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , 
+                        fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr()))
+
+            tdSql.execute('''insert into bj_stable_1_5_negative (ts , q_int , q_bigint , q_smallint , q_tinyint , q_float , q_double, q_bool , q_binary , q_nchar, q_ts,\
+                        q_binary1 , q_nchar1 , q_binary2 , q_nchar2 , q_binary3 , q_nchar3 , q_binary4 , q_nchar4 , q_binary5 , q_nchar5 , q_binary6 , q_nchar6 , q_binary7 , q_nchar7, q_binary8 , q_nchar8) \
+                        values(%d, %d, %d, %d, %d, %f, %f, 0, 'binary.%s', 'nchar.%s', %d, 'binary1.%s', 'nchar1.%s', 'binary2.%s', 'nchar2.%s', 'binary3.%s', 'nchar3.%s', \
+                        'binary4.%s', 'nchar4.%s', 'binary5.%s', 'nchar5.%s', 'binary6.%s', 'nchar6.%s', 'binary7.%s', 'nchar7.%s', 'binary8.%s', 'nchar8.%s') ;''' 
+                        % (ts + i*1000 +10, fake.random_int(min=-0, max=2147483647, step=1), 
+                        fake.random_int(min=-0, max=9223372036854775807, step=1), 
+                        fake.random_int(min=-0, max=32767, step=1) , fake.random_int(min=-0, max=127, step=1) , 
+                        fake.pyfloat() , fake.pyfloat() , fake.pystr() , fake.pystr() , ts + i, fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , 
+                        fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr() , fake.pystr()))
+            
         tdSql.query("select count(*) from stable_1;")
-        tdSql.checkData(0,0,5*num_random*n)
+        tdSql.checkData(0,0,10*num_random*n)
         tdSql.query("select count(*) from hn_table_1_r;")
         tdSql.checkData(0,0,num_random*n)
         
@@ -220,39 +322,28 @@ class TDTestCase:
         
         
         tdSql.query(" select * from information_schema.ins_databases where name = '%s';" %database)
-        print(tdSql.queryResult)
-        
-        # tdSql.query(" select table_prefix,table_suffix from information_schema.ins_databases where name = '%s';" %database)
-        # print(tdSql.queryResult)
-        #TD-19082
-        
-        #tdSql.query(" select * from information_schema.ins_tables where db_name = '%s';" %database)
-        #print(tdSql.queryResult)
+        tdLog.info(tdSql.queryResult)
         
-        tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s';" %database)  
+        tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' limit 3;" %database)  
         queryRows = len(tdSql.queryResult)    
         for i in range(queryRows):
-            print("row=%d,  vgroup_id=%s,  tbname=%s " %(i,tdSql.queryResult[i][1],tdSql.queryResult[i][0]))
+            tdLog.info("row=%d,  vgroup_id=%s,  tbname=%s " %(i,tdSql.queryResult[i][1],tdSql.queryResult[i][0]))
         
         tdLog.info("\n=============flush database ====================\n")
         
         tdSql.execute(" flush database %s;" %database)
         
         tdSql.query(" select * from information_schema.ins_databases where name = '%s';" %database)
-        print(tdSql.queryResult)
-        
-        # tdSql.query(" select table_prefix,table_suffix from information_schema.ins_databases where name = '%s';" %database)
-        # print(tdSql.queryResult)
-        #TD-19082
-        
-        tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s';" %database)
+        tdLog.info(tdSql.queryResult)
+               
+        tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' limit 3;" %database)
         queryRows = len(tdSql.queryResult)    
         for i in range(queryRows):
-            print("row=%d,  vgroup_id=%s,  tbname=%s " %(i,tdSql.queryResult[i][1],tdSql.queryResult[i][0]))
+            tdLog.info("row=%d,  vgroup_id=%s,  tbname=%s " %(i,tdSql.queryResult[i][1],tdSql.queryResult[i][0]))
 
 
         # check in one vgroup
-        if check_result == 'Y':
+        if check_result_positive == 'Y':
             #base table : sh_table_0_a
             tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name='sh_table_0_a';" %(database))
             base_value_table_name = tdSql.queryResult[0][0]
@@ -324,8 +415,100 @@ class TDTestCase:
                 tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name='tj_table_%d_b';" %(database,i))
                 self.value_check(base_value_table_name,base_value_table_vgroup)
                          
+        elif check_result_negative == 'Y':
+            #base table : sh_table_0_a
+            tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name='sh_table_0_a_negative';" %(database))
+            base_value_table_name = tdSql.queryResult[0][0]
+            base_value_table_vgroup = tdSql.queryResult[0][1]
+            
+            #check table :sh_table_i_a
+            check_rows = tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name like 'sh_table_%%_a_negative';" %(database))
+            for i in range(check_rows):
+                tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name='sh_table_%d_a_negative';" %(database,i))
+                self.value_check(base_value_table_name,base_value_table_vgroup)
+                        
+            #check table :sh_table_i_b
+            check_rows = tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name like 'sh_table_%%_b_negative';" %(database))
+            for i in range(check_rows):
+                tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name='sh_table_%d_b_negative';" %(database,i))
+                self.value_check(base_value_table_name,base_value_table_vgroup) 
+                       
+            #check table :sh_table_i_c
+            check_rows = tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name like 'sh_table_%%_c_negative';" %(database))
+            for i in range(check_rows):
+                tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name='sh_table_%d_c_negative';" %(database,i))
+                self.value_check(base_value_table_name,base_value_table_vgroup)
+                    
+            #check table :sh_table_i_r
+            check_rows = tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name like 'sh_table_%%_r_negative';" %(database))
+            for i in range(check_rows):
+                tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name='sh_table_%d_r_negative';" %(database,i))
+                self.value_check(base_value_table_name,base_value_table_vgroup)
+                
+            #base table : bj_table_0_a
+            tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name='bj_table_0_a_negative';" %(database))
+            base_value_table_name = tdSql.queryResult[0][0]
+            base_value_table_vgroup = tdSql.queryResult[0][1]
+                
+            #check table :bj_table_i_a
+            check_rows = tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name like 'bj_table_%%_a_negative';" %(database))
+            for i in range(check_rows):
+                tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name='bj_table_%d_a_negative';" %(database,i))
+                self.value_check(base_value_table_name,base_value_table_vgroup)
+                
+            #check table :bj_table_i_b
+            check_rows = tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name like 'bj_table_%%_b_negative';" %(database))
+            for i in range(check_rows):
+                tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name='bj_table_%d_b_negative';" %(database,i))
+                self.value_check(base_value_table_name,base_value_table_vgroup)
+                
+            #check table :bj_table_i_c
+            check_rows = tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name like 'bj_table_%%_c_negative';" %(database))
+            for i in range(check_rows):
+                tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name='bj_table_%d_c_negative';" %(database,i))
+                self.value_check(base_value_table_name,base_value_table_vgroup)
+                
+            #check table :bj_table_i_r
+            check_rows = tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name like 'bj_table_%%_r_negative';" %(database))
+            for i in range(check_rows):
+                tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name='bj_table_%d_r_negative';" %(database,i))
+                self.value_check(base_value_table_name,base_value_table_vgroup)
+                
+            #base table : hn_table_0_r
+            tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name='hn_table_0_r_negative';" %(database))
+            base_value_table_name = tdSql.queryResult[0][0]
+            base_value_table_vgroup = tdSql.queryResult[0][1]
+            
+            #check table :hn_table_i_r
+            check_rows = tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name like 'hn_table_%%_r_negative';" %(database))
+            for i in range(check_rows):
+                tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name='hn_table_%d_r_negative';" %(database,i))
+                self.value_check(base_value_table_name,base_value_table_vgroup)
+                
+                
+            #base table : tj_table_0_r
+            tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name='tj_table_0_a_negative';" %(database))
+            base_value_table_name = tdSql.queryResult[0][0]
+            base_value_table_vgroup = tdSql.queryResult[0][1]
+            
+            #check table :tj_table_i_a
+            check_rows = tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name like 'tj_table_%%_a_negative';" %(database))
+            for i in range(check_rows):
+                tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name='tj_table_%d_a_negative';" %(database,i))
+                self.value_check(base_value_table_name,base_value_table_vgroup)
+                
+            #check table :tj_table_i_b
+            check_rows = tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name like 'tj_table_%%_b_negative';" %(database))
+            for i in range(check_rows):
+                tdSql.query(" select table_name,vgroup_id from information_schema.ins_tables where db_name = '%s' and table_name='tj_table_%d_b_negative';" %(database,i))
+                self.value_check(base_value_table_name,base_value_table_vgroup)
+                
+                
         else:
             pass
+        
+        tdLog.info(f"create end:n:{n},vgroups:{vgroups},table_prefix:{table_prefix},table_suffix:{table_suffix},check_result_positive:{check_result_positive},check_result_negative:{check_result_negative}") 
+        
     
     def value_check(self,base_value_table_name,base_value_table_vgroup):
         check_value_table_name = tdSql.queryResult[0][0]
@@ -348,17 +531,28 @@ class TDTestCase:
                   
         os.system("rm -rf %s/%s.sql" % (self.testcasePath,self.testcaseFilename)) 
         
-        #(self,database,n,vgroups,table_prefix,table_suffix)
-        self.dropandcreateDB_random("%s" %self.db, 1,2,0,0,'N')
-        self.dropandcreateDB_random("%s" %self.db, 1,2,0,2,'N')
-        self.dropandcreateDB_random("%s" %self.db, 1,2,2,0,'N')
-        self.dropandcreateDB_random("%s" %self.db, 1,2,3,3,'Y')  
-        self.dropandcreateDB_random("%s" %self.db, 1,3,3,3,'Y')  
-        self.dropandcreateDB_random("%s" %self.db, 1,4,4,4,'Y')
-        self.dropandcreateDB_random("%s" %self.db, 1,5,5,5,'Y')
+        #(self,database,n,vgroups,table_prefix,table_suffix,check_result_positive,check_result_negative):
+        #check_result_positive 检查前缀后缀是正数的，check_result_negative 检查前缀后缀是负数的(TS-3249)
+        # self.dropandcreateDB_random("%s" %self.db, 1,2,0,0,'N','N')
+        # self.dropandcreateDB_random("%s" %self.db, 1,2,0,2,'N','N')
+        # self.dropandcreateDB_random("%s" %self.db, 1,2,2,0,'N','N')        
+        
+        self.dropandcreateDB_random("%s" %self.db, 1,random.randint(1,5),random.randint(0,3),random.randint(0,3),'N','N')
+        self.dropandcreateDB_random("%s" %self.db, 1,random.randint(1,5),random.randint(-10,0),random.randint(-10,0),'N','N')
+        self.dropandcreateDB_random("%s" %self.db, 1,random.randint(1,5),random.randint(-191,0),random.randint(-191,0),'N','N')
+        self.dropandcreateDB_random("%s" %self.db, 1,random.randint(1,5),random.randint(0,100),random.randint(0,91),'N','N')
+        
+        # self.dropandcreateDB_random("%s" %self.db, 1,2,3,3,'Y','N')  
+        # self.dropandcreateDB_random("%s" %self.db, 1,3,3,3,'Y','N')  
+        # self.dropandcreateDB_random("%s" %self.db, 1,4,4,4,'Y','N')
+        # self.dropandcreateDB_random("%s" %self.db, 1,5,5,5,'Y','N')       
+        self.dropandcreateDB_random("%s" %self.db, 1,random.randint(1,5),random.randint(3,5),random.randint(3,5),'Y','N')
+                
+        self.dropandcreateDB_random("%s" %self.db, 1,random.randint(1,5),random.randint(-5,-1),0,'N','Y')        
+        self.dropandcreateDB_random("%s" %self.db, 1,random.randint(1,5),random.randint(-5,-1),random.randint(-9,-0),'N','Y')
         
         
-        #taos -f sql
+        # #taos -f sql
         print("taos -f sql start!")
         taos_cmd1 = "taos -f %s/%s.sql" % (self.testcasePath,self.testcaseFilename)
         _ = subprocess.check_output(taos_cmd1, shell=True)
diff --git a/tests/system-test/2-query/select_null.py b/tests/system-test/2-query/select_null.py
new file mode 100755
index 0000000000000000000000000000000000000000..68eea8bc67cad78d44b3c5bd3ad7888b06e9cc00
--- /dev/null
+++ b/tests/system-test/2-query/select_null.py
@@ -0,0 +1,446 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import random
+import os
+import time
+import taos
+import subprocess
+from faker import Faker
+from util.log import tdLog
+from util.cases import tdCases
+from util.sql import tdSql
+from util.dnodes import tdDnodes
+from util.dnodes import *
+
+class TDTestCase:
+    
+    def init(self, conn, logSql, replicaVar):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor(), logSql)
+
+        self.testcasePath = os.path.split(__file__)[0]
+        self.testcaseFilename = os.path.split(__file__)[-1]
+        os.system("rm -rf %s/%s.sql" % (self.testcasePath,self.testcaseFilename))
+        
+        self.db = "sel_null"
+
+    def insert_data(self,database,vgroups):
+        num_random = 10
+        tdSql.execute('''drop database if exists %s ;''' %database)
+        tdSql.execute('''create database %s keep 36500 vgroups %d PRECISION 'us';'''%(database,vgroups))
+        tdSql.execute('''use %s;'''%database)
+
+        tdSql.execute('''create stable %s.stb0 (ts timestamp , c0 int , c1 double , c0null int , c1null double ) tags( t0 tinyint , t1 varchar(16) , t_int int , t_bigint bigint , t_smallint smallint , t_tinyint tinyint , t_bool bool , t_binary binary(100) , t_nchar nchar(100) ,t_float float , t_double double , t_ts timestamp);'''%database)
+
+        for i in range(5):
+            tdSql.execute('''create table %s.stb0_%d using %s.stb0 tags(%d,'varchar%d',%d,%d, %d, %d,%d,'binary%d','nchar%d',%d,%d,%d ) ;'''%(database,i,database,i,i,i,i,i,i,i,i,i,i,i,i))
+            
+        # insert data
+        for i in range(num_random):   
+            for j in range(50):     
+                tdSql.execute('''insert into %s.stb0_0  (ts , c1 , c0) values(now, %d, %d) ;''' % (database,j,j))
+                tdSql.execute('''insert into %s.stb0_1  (ts , c1 , c0) values(now, %d, %d) ;''' % (database,j,j))
+                tdSql.execute('''insert into %s.stb0_2  (ts , c1 , c0) values(now, %d, %d) ;''' % (database,j,j))
+                tdSql.execute('''insert into %s.stb0_3  (ts , c1 , c0) values(now, %d, %d) ;''' % (database,j,j))
+                tdSql.execute('''insert into %s.stb0_4  (ts , c1 , c0) values(now, %d, %d) ;''' % (database,j,j))
+
+        tdSql.query("select count(*) from %s.stb0;" %database)
+        tdSql.checkData(0,0,5*num_random*50)
+        tdSql.query("select count(*) from %s.stb0_0;"%database)
+        tdSql.checkData(0,0,num_random*50)
+        
+    def ts_3085(self,database):  
+        sql = "select count(c0null) from(select * from %s.stb0 limit 20,4) "%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        
+        offset =  random.randint(10,100)
+        for i in range(offset):
+            sql = "select count(c0null) from(select * from %s.stb0 limit %d,%d) "%(database,offset,i)
+            tdSql.query(sql) 
+            tdSql.checkData(0,0,0)
+            sql = "select count(c1null) from(select * from %s.stb0 limit %d,%d) "%(database,offset,i)
+            tdSql.query(sql) 
+            tdSql.checkData(0,0,0)
+            sql = "select count(c0) from(select * from %s.stb0 limit %d,%d) "%(database,offset,i)
+            tdSql.query(sql) 
+            tdSql.checkData(0,0,i)
+            sql = "select count(c1) from(select * from %s.stb0 limit %d,%d) "%(database,offset,i)
+            tdSql.query(sql) 
+            tdSql.checkData(0,0,i)
+            sql = "select count(t0) from(select * from %s.stb0 limit %d,%d) "%(database,offset,i)
+            tdSql.query(sql) 
+            tdSql.checkData(0,0,i)
+            sql = "select count(t1) from(select * from %s.stb0 limit %d,%d) "%(database,offset,i)
+            tdSql.query(sql) 
+            tdSql.checkData(0,0,i)
+
+
+    def ts_2974_max(self,database):  
+        sql = "select max(c0) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,49)
+        sql = "select max(c0),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,49)
+        sql = "select max(c1) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,49)
+        sql = "select max(c1),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,49)
+        
+        sql = "select max(c0null) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,"None")
+        sql = "select max(c0null),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,"None")
+        sql = "select max(c1null) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,"None")
+        sql = "select max(c1null),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,"None") 
+        
+        sql = "select max(t0) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,4)
+        sql = "select max(t0),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,4)
+        sql = "select max(t1) from %s.stb0 where ts<now;"%(database)
+        tdSql.error(sql) 
+        sql = "select max(t1),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.error(sql) 
+        sql = "select max(t_bool) from %s.stb0 where ts<now;"%(database)
+        tdSql.error(sql) 
+        sql = "select max(t_bool),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.error(sql) 
+        sql = "select max(t_binary) from %s.stb0 where ts<now;"%(database)
+        tdSql.error(sql) 
+        sql = "select max(t_binary),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.error(sql) 
+        sql = "select max(t_nchar) from %s.stb0 where ts<now;"%(database)
+        tdSql.error(sql) 
+        sql = "select max(t_nchar),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.error(sql) 
+        sql = "select max(t_int) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,4)
+        sql = "select max(t_int),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,4)
+        sql = "select max(t_int) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,4)
+        sql = "select max(t_int),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,4)
+        sql = "select max(t_int) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,4)
+        sql = "select max(t_int),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,4)
+        sql = "select max(t_bigint) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,4)
+        sql = "select max(t_bigint),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,4)
+        sql = "select max(t_smallint) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,4)
+        sql = "select max(t_smallint),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,4)
+        sql = "select max(t_tinyint) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,4)
+        sql = "select max(t_tinyint),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,4)
+        sql = "select max(t_float) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,4)
+        sql = "select max(t_float),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,4)
+        sql = "select max(t_double) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,4)
+        sql = "select max(t_double),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,4)
+        
+    def ts_2974_min(self,database):  
+        sql = "select min(c0) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        sql = "select min(c0),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        sql = "select min(c1) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        sql = "select min(c1),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        
+        sql = "select min(c0null) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,"None")
+        sql = "select min(c0null),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,"None")
+        sql = "select min(c1null) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,"None")
+        sql = "select min(c1null),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,"None") 
+        
+        sql = "select min(t0) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        sql = "select min(t0),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        sql = "select min(t1) from %s.stb0 where ts<now;"%(database)
+        tdSql.error(sql) 
+        sql = "select min(t1),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.error(sql) 
+        sql = "select min(t_bool) from %s.stb0 where ts<now;"%(database)
+        tdSql.error(sql) 
+        sql = "select min(t_bool),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.error(sql) 
+        sql = "select min(t_binary) from %s.stb0 where ts<now;"%(database)
+        tdSql.error(sql) 
+        sql = "select min(t_binary),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.error(sql) 
+        sql = "select min(t_nchar) from %s.stb0 where ts<now;"%(database)
+        tdSql.error(sql) 
+        sql = "select min(t_nchar),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.error(sql) 
+        sql = "select min(t_int) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        sql = "select min(t_int),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        sql = "select min(t_int) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        sql = "select min(t_int),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        sql = "select min(t_int) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        sql = "select min(t_int),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        sql = "select min(t_bigint) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        sql = "select min(t_bigint),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        sql = "select min(t_smallint) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        sql = "select min(t_smallint),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        sql = "select min(t_tinyint) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        sql = "select min(t_tinyint),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        sql = "select min(t_float) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        sql = "select min(t_float),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        sql = "select min(t_double) from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        sql = "select min(t_double),ts from %s.stb0 where ts<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,0)
+        
+    def ts_2601(self,database): 
+        
+        tdSql.query("alter local 'keepcolumnname' '0';")  
+        sql = "select ts,c0 from (select last(*) from %s.stb0 where ts<now);"%(database)
+        tdSql.error(sql) 
+        sql = "select ts,c0 from (select last(*) from %s.stb0 where ts<now order by ts );"%(database)
+        tdSql.error(sql) 
+        
+        tdSql.query("alter local 'keepcolumnname' '1';")         
+        sql = "select ts,c0 from (select last(*) from %s.stb0 where ts<now);"%(database)
+        tdSql.query(sql) 
+        sql = "select ts,c0 from (select last(*) from %s.stb0 where ts<now order by ts );"%(database)
+        tdSql.query(sql) 
+        
+    def ts_3108(self,database): 
+         
+        sql = "select count(*) from %s.stb0 where to_unixtimestamp('2023-01-01 00:00:00.000')<now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,2500)
+        sql = "select count(*) from %s.stb0 where to_unixtimestamp('2023-01-01 00:00:00.000')>now;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkRows(0)
+        
+        sql = "select count(*) from %s.stb0 where to_unixtimestamp('2024-01-01 00:00:00.000')<now+1y;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,0,2500)
+        sql = "select count(*) from %s.stb0 where to_unixtimestamp('2024-01-01 00:00:00.000')>now+1y;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkRows(0)
+        
+    def ts_3110(self,database): 
+         
+        sql1 = "select * from %s.stb0 order by ts desc limit 2;"%(database)
+        tdSql.query(sql1) 
+        data1_0_0 = tdSql.getData(0,0)
+        data1_1_0 = tdSql.getData(1,0)
+        
+        sql2 = "select * from (select * from %s.stb0 order by ts desc limit 2) order by ts;"%(database)
+        tdSql.query(sql2) 
+        data2_0_0 = tdSql.getData(0,0)
+        data2_1_0 = tdSql.getData(1,0)
+        
+        if (data1_0_0 == data2_1_0) and (data1_1_0 == data2_0_0):
+            tdLog.info("ts_3110: success")
+        else:
+            tdLog.exit("ts_3110: sql1 result:'%s' not equal sql2 result:'%s'" % (sql1,sql2))
+        
+    def ts_3036(self,database): 
+         
+        sql1 = "select ts , c0 , c1 , c0null , c1null from (select ts , c0 , c1 , c0null , c1null from %s.stb0_0 where ts between now -1d and now +1d \
+            union all select ts , c0 , c1 , c0null , c1null from %s.stb0_1 where ts between now -1d and now +1d \
+            union all select ts , c0 , c1 , c0null , c1null from %s.stb0_2 where ts between now -1d and now +1d ) tt \
+            where ts < now order by tt.ts desc limit 2;"%(database,database,database)
+        tdSql.query(sql1) 
+        data1_0_0 = tdSql.getData(0,0)
+        data1_1_0 = tdSql.getData(1,0)
+        
+        sql2 = "select ts , c0 , c1 , c0null , c1null  from (select tbname as tb, ts , c0 , c1 , c0null , c1null from %s.stb0 where ts > now  \
+            union all select tbname as tb, ts , c0 , c1 , c0null , c1null from %s.stb0 where ts = now  \
+            union all select tbname as tb, ts , c0 , c1 , c0null , c1null from %s.stb0 where ts < now ) tt \
+            where tt.ts between now -1d and now +1d  and tt.tb in ('stb0_0','stb0_1','stb0_2') order by tt.ts desc limit 2;"%(database,database,database)
+        tdSql.query(sql2) 
+        data2_0_0 = tdSql.getData(0,0)
+        data2_1_0 = tdSql.getData(1,0)
+        
+        sql3 = "select ts , c0 , c1 , c0null , c1null  from %s.stb0  \
+            where ts between now -1d and now +1d  and tbname in ('stb0_0','stb0_1','stb0_2') order by ts desc limit 2;"%(database)
+        tdSql.query(sql3) 
+        data3_0_0 = tdSql.getData(0,0)
+        data3_1_0 = tdSql.getData(1,0)
+        
+        if (data1_0_0 == data2_0_0 == data3_0_0) and (data1_1_0 == data2_1_0 == data3_1_0):
+            tdLog.info("ts_3036: success")
+        else:
+            tdLog.exit("ts_3036: sql1 result:'%s' not equal sql2 result:'%s' or not equal sql3 result:'%s'" % (sql1,sql2,sql3))
+        
+        
+    def ts_23569(self,database): 
+        
+        tdSql.query("alter local 'keepcolumnname' '0';") 
+        sql = "alter table %s.stb0 drop tag t10;"%(database)
+        tdSql.error(sql) 
+        error_msg = tdSql.error(sql) 
+        include_msg = 'Invalid tag name'
+        if include_msg in error_msg:
+            tdLog.info("ts_23569: success")
+        else:
+            tdLog.exit("ts_23569: include_msg:'%s' not in error_msg:'%s'" % (include_msg,error_msg))
+        
+        tdSql.query("alter local 'keepcolumnname' '1';")         
+        sql = "alter table %s.stb0 drop tag t10;"%(database)
+        tdSql.error(sql) 
+        error_msg = tdSql.error(sql) 
+        include_msg = 'Invalid tag name'
+        if include_msg in error_msg:
+            tdLog.info("ts_23569: success")
+        else:
+            tdLog.exit("ts_23569: include_msg:'%s' not in error_msg:'%s'" % (include_msg,error_msg))
+            
+    def ts_23505(self,database): 
+        
+        sql = "create table %s.`12345` (`567` timestamp,num int);"%(database)
+        tdSql.execute(sql)
+        
+        sql = "insert into %s.12345 values (now,1);"%(database)
+        tdSql.error(sql) 
+        
+        sql = "insert into %s.`12345` values (now,1);"%(database)
+        tdSql.execute(sql) 
+        
+        sql = "select * from %s.`12345` order by `567` desc limit 2;"%(database)
+        tdSql.query(sql) 
+        tdSql.checkData(0,1,1)
+        
+        sql = "drop table %s.`12345` ;"%(database)
+        tdSql.execute(sql) 
+        sql = "select * from %s.`12345` order by `567` desc limit 2;"%(database)
+        tdSql.error(sql) 
+                            
+    def run(self):    
+        startTime = time.time()  
+                  
+        os.system("rm -rf %s/%s.sql" % (self.testcasePath,self.testcaseFilename)) 
+        
+        self.insert_data("%s" %self.db,2)
+        
+        self.ts_3085("%s" %self.db)
+        self.ts_2974_max("%s" %self.db)
+        self.ts_2974_min("%s" %self.db)
+        self.ts_2601("%s" %self.db)
+        self.ts_23569("%s" %self.db)
+        self.ts_3108("%s" %self.db)
+        self.ts_3110("%s" %self.db)
+        self.ts_23505("%s" %self.db)
+        self.ts_3036("%s" %self.db)
+        
+        tdSql.query("flush database %s" %self.db) 
+        
+        self.ts_2974_max("%s" %self.db)
+        self.ts_2974_min("%s" %self.db)
+        self.ts_3085("%s" %self.db)
+        self.ts_2601("%s" %self.db)
+        self.ts_23569("%s" %self.db)
+        self.ts_3108("%s" %self.db)
+        self.ts_3110("%s" %self.db)
+        self.ts_23505("%s" %self.db)
+        self.ts_3036("%s" %self.db)
+            
+            
+        endTime = time.time()
+        print("total time %ds" % (endTime - startTime))
+    
+
+
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/system-test/2-query/slimit.py b/tests/system-test/2-query/slimit.py
new file mode 100644
index 0000000000000000000000000000000000000000..48209da59a081a923884770a05cfd118f1e953b5
--- /dev/null
+++ b/tests/system-test/2-query/slimit.py
@@ -0,0 +1,1821 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+import os
+import random
+import re
+
+from util.log import *
+from util.cases import *
+from util.sql import *
+from util.dnodes import *
+
+
+class TDTestCase:
+    def init(self, conn, logSql, replicaVar):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor(), logSql)
+
+        self.testcasePath = os.path.split(__file__)[0]
+        self.testcaseFilename = os.path.split(__file__)[-1]
+        os.system("rm -rf %s/%s.sql" % (self.testcasePath,self.testcaseFilename))
+
+    def getBuildPath(self):
+        selfPath = os.path.dirname(os.path.realpath(__file__))
+
+        if ("community" in selfPath):
+            projPath = selfPath[:selfPath.find("community")]
+        else:
+            projPath = selfPath[:selfPath.find("tests")]
+
+        for root, dirs, files in os.walk(projPath):
+            if ("taosd" in files):
+                rootRealPath = os.path.dirname(os.path.realpath(root))
+                if ("packaging" not in rootRealPath):
+                    buildPath = root[:len(root)-len("/build/bin")]
+                    break
+        return buildPath
+
+    def run_benchmark(self,dbname,tables,per_table_num,vgroups,replica):
+        buildPath = self.getBuildPath()
+        if (buildPath == ""):
+            tdLog.exit("taosd not found!")
+        else:
+            tdLog.info("taosd found in %s" % buildPath)
+        binPath = buildPath+ "/build/bin/"
+
+        print("%staosBenchmark -d %s -t %d -n %d  -v %d -a %d -y " % (binPath,dbname,tables,per_table_num,vgroups,replica))
+        os.system("%staosBenchmark -d %s -t %d -n %d  -v %d -a %d -y " % (binPath,dbname,tables,per_table_num,vgroups,replica))
+
+    def sql_query_time_cost(self,sql):
+        startTime = time.time()
+        tdSql.query(sql)
+        endTime = time.time()
+        tdLog.info("sql:%s query time cost (%d)s" % (sql,endTime - startTime))
+    
+    def sql_limit_retun_n_slimit_return_error(self,sql,num,tables,per_table_num,base_fun,replace_fun):   
+        #sql limit n = n;sql limit 0 = 0 ;sql slmit n = error;sql slimit 0  = error  
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+          
+        nest_sql =" select * from (%s) " %sql
+        self.sql_query_time_cost(sql)
+        tdSql.checkRows(num)        
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkRows(num)
+        
+        sql_0 = re.sub(r'\d\d',"0",sql) # \d是匹配数字字符[0-9]，+匹配一个或多个
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkRows(0)
+        
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql) # \d是匹配数字字符[0-9]，+匹配一个或多个
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkRows(0)
+        
+        sql = sql.replace('limit','slimit')
+        tdSql.error(sql)
+        nest_sql = nest_sql.replace('limit','slimit')
+        tdSql.error(nest_sql)
+               
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        tdSql.error(sql_0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        tdSql.error(nest_sql_0)
+
+    def sql_data_limit_retun_n_slimit_return_error(self,sql,num,tables,per_table_num,base_fun,replace_fun):   
+        #sql limit n = n;sql limit 0 = 0 ;sql slmit n = error;sql slimit 0  = error  
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+         
+        nest_sql =" select * from (%s) " %sql
+        self.sql_query_time_cost(sql)
+        tdSql.checkData(0,0,num)        
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkData(0,0,num) 
+        
+        sql_0 = re.sub(r'\d\d',"0",sql) # \d是匹配数字字符[0-9]，+匹配一个或多个
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkData(0,0,0) 
+        
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql) # \d是匹配数字字符[0-9]，+匹配一个或多个
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkData(0,0,0) 
+        
+        sql = sql.replace('limit','slimit')
+        tdSql.error(sql)
+        nest_sql = nest_sql.replace('limit','slimit')
+        tdSql.error(nest_sql)
+               
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        tdSql.error(sql_0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        tdSql.error(nest_sql_0)
+        
+        
+    def sql_limit_retun_1_slimit_return_error(self,sql,tables,per_table_num,base_fun,replace_fun): 
+        #sql limit n =1;sql limit 0 = 0 ;sql slmit n = error;sql slimit 0  = error 
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+        
+        nest_sql =" select * from (%s) " %sql       
+        self.sql_query_time_cost(sql)
+        tdSql.checkRows(1)       
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkRows(1)        
+        
+        sql_0 = re.sub(r'\d+',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkRows(0)
+        
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql) # \d是匹配数字字符[0-9]，+匹配一个或多个
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkRows(0)
+        
+        sql = sql.replace('limit','slimit')
+        tdSql.error(sql)
+        nest_sql = nest_sql.replace('limit','slimit')
+        tdSql.error(nest_sql)
+        
+        sql_0 = re.sub(r'\d+',"0",sql)
+        tdSql.error(sql_0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        tdSql.error(nest_sql_0)
+        
+    def sql_data_limit_retun_1_slimit_return_error(self,sql,tables,per_table_num,base_fun,replace_fun): 
+        #sql limit n =1;sql limit 0 = 0 ;sql slmit n = error;sql slimit 0  = error 
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+         
+        nest_sql =" select * from (%s) " %sql       
+        self.sql_query_time_cost(sql)
+        tdSql.checkData(0,0,1)        
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkData(0,0,1)         
+        
+        sql_0 = re.sub(r'\d+',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkData(0,0,0) 
+        
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql) # \d是匹配数字字符[0-9]，+匹配一个或多个
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkData(0,0,0) 
+        
+        sql = sql.replace('limit','slimit')
+        tdSql.error(sql)
+        nest_sql = nest_sql.replace('limit','slimit')
+        tdSql.error(nest_sql)
+        
+        sql_0 = re.sub(r'\d+',"0",sql)
+        tdSql.error(sql_0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        tdSql.error(nest_sql_0)
+        
+    def sql_last_limit_retun_1_slimit_return_error(self,sql,tables,per_table_num,base_fun,replace_fun): 
+        #sql limit n =1;sql limit 0 = 0 ;sql slmit n = error;sql slimit 0  = error 
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+         
+        nest_sql =" select * from (%s) " %sql       
+        self.sql_query_time_cost(sql)
+        rows = tdSql.queryRows
+        if (rows >= 1 or rows <= 4):
+            tdLog.info("sql checkrows success")
+        else:
+            tdLog.exit(f"checkEqual error, sql_rows=={rows}")
+            
+            
+        self.sql_query_time_cost(nest_sql)
+        rows = tdSql.queryRows
+        if (rows >= 1 or rows <= 4):
+            tdLog.info("sql checkrows success")
+        else:
+            tdLog.exit(f"checkEqual error, sql_rows=={rows}")         
+        
+        sql_0 = re.sub(r'\d+',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkRows(0)
+        
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql) # \d是匹配数字字符[0-9]，+匹配一个或多个
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkRows(0)
+        
+        sql = sql.replace('limit','slimit')
+        tdSql.error(sql)
+        nest_sql = nest_sql.replace('limit','slimit')
+        tdSql.error(nest_sql)
+        
+        sql_0 = re.sub(r'\d+',"0",sql)
+        tdSql.error(sql_0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        tdSql.error(nest_sql_0)
+        
+    def sql_limit_retun_tables_slimit_return_error(self,sql,num,tables,per_table_num,base_fun,replace_fun): 
+        #sql limit n =n;sql limit 0 = 0 ;sql slmit n = error;sql slimit 0  = error  
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+          
+        nest_sql =" select * from (%s) " %sql         
+        self.sql_query_time_cost(sql)
+        tdSql.checkRows(tables)     
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkRows(tables)  
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkRows(0)
+        
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql) # \d是匹配数字字符[0-9]，+匹配一个或多个
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkRows(0)
+        
+        sql = sql.replace('limit','slimit')
+        tdSql.error(sql)
+        nest_sql = nest_sql.replace('limit','slimit')
+        tdSql.error(nest_sql)
+        
+        sql_0 = re.sub(r'\d+',"0",sql)
+        tdSql.error(sql_0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        tdSql.error(nest_sql_0)
+
+    def sql_limit_retun_tables_slimit_return_n(self,sql,num,tables,per_table_num,base_fun,replace_fun): 
+        #sql limit n =tables;sql limit 0 = 0 ;sql slmit n = n;sql slimit 0  = 0   
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+         
+        nest_sql =" select * from (%s) " %sql           
+        self.sql_query_time_cost(sql)
+        tdSql.checkRows(tables)  
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkRows(tables)  
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkRows(0)
+        
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql) # \d是匹配数字字符[0-9]，+匹配一个或多个
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkRows(0)
+        
+        sql = sql.replace('limit','slimit')
+        self.sql_query_time_cost(sql)
+        tdSql.checkRows(num)
+        nest_sql = nest_sql.replace('limit','slimit')
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkRows(num)
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkRows(0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkRows(0)
+
+    def sql_data_limit_retun_tables_slimit_return_n(self,sql,num,tables,per_table_num,base_fun,replace_fun): 
+        #sql limit n =tables;sql limit 0 = 0 ;sql slmit n = n;sql slimit 0  = 0   
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+         
+        nest_sql =" select * from (%s) " %sql           
+        self.sql_query_time_cost(sql)
+        tdSql.checkData(0,0,tables)  
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkData(0,0,tables)  
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkData(0,0,0)
+        
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql) # \d是匹配数字字符[0-9]，+匹配一个或多个
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkData(0,0,0)
+        
+        sql = sql.replace('limit','slimit')
+        self.sql_query_time_cost(sql)
+        tdSql.checkData(0,0,num)
+        nest_sql = nest_sql.replace('limit','slimit')
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkData(0,0,num)
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkData(0,0,0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkData(0,0,0)
+
+    def sql_limit_retun_n_slimit_return_tables(self,sql,num,tables,per_table_num,base_fun,replace_fun): 
+        #sql limit n =n;sql limit 0 = 0 ;sql slmit n = 100;sql slimit 0  = 0    
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+         
+        nest_sql =" select * from (%s) " %sql            
+        self.sql_query_time_cost(sql)
+        tdSql.checkRows(num)
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkRows(num) 
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkRows(0)
+        
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql) # \d是匹配数字字符[0-9]，+匹配一个或多个
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkRows(0)
+        
+        sql = sql.replace('limit','slimit')
+        self.sql_query_time_cost(sql)
+        tdSql.checkRows(tables)
+        nest_sql = nest_sql.replace('limit','slimit')
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkRows(tables)
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkRows(0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkRows(0)
+
+    def sql_data_limit_retun_n_slimit_return_tables(self,sql,num,tables,per_table_num,base_fun,replace_fun): 
+        #sql limit n =n;sql limit 0 = 0 ;sql slmit n = 100;sql slimit 0  = 0  
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+           
+        nest_sql =" select * from (%s) " %sql            
+        self.sql_query_time_cost(sql)
+        tdSql.checkData(0,0,num)
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkData(0,0,num) 
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkData(0,0,0)
+        
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql) # \d是匹配数字字符[0-9]，+匹配一个或多个
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkData(0,0,0)
+        
+        sql = sql.replace('limit','slimit')
+        self.sql_query_time_cost(sql)
+        tdSql.checkData(0,0,tables)
+        nest_sql = nest_sql.replace('limit','slimit')
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkData(0,0,tables)
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkData(0,0,0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkData(0,0,0)
+
+    def sql_limit_retun_tables_times_n_slimit_return_error(self,sql,num,tables,per_table_num,base_fun,replace_fun): 
+        #sql limit n =n*tables;sql limit 0 = 0 ;sql slmit n = tables*n;sql slimit 0  = 0   
+        #interval     
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+         
+        nest_sql =" select * from (%s) " %sql   
+        self.sql_query_time_cost(sql)
+        tdSql.checkRows(num*tables)
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkRows(num*tables) 
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkRows(0)
+        
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql) # \d是匹配数字字符[0-9]，+匹配一个或多个
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkRows(0)
+        
+        sql = sql.replace('limit','slimit')
+        tdSql.error(sql)
+        nest_sql = nest_sql.replace('limit','slimit')
+        tdSql.error(nest_sql)
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        tdSql.error(sql_0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        tdSql.error(nest_sql_0)
+
+    def sql_limit_retun_tables_times_n_slimit_return_per_table_num_times_n(self,sql,num,tables,per_table_num,base_fun,replace_fun): 
+        #sql limit n =n*tables;sql limit 0 = 0 ;sql slmit n = per_table_num*n;sql slimit 0  = 0   
+        #interval   
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+         
+        nest_sql =" select * from (%s) " %sql     
+        self.sql_query_time_cost(sql)
+        tdSql.checkRows(num*tables)
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkRows(num*tables) 
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkRows(0)
+        
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql) # \d是匹配数字字符[0-9]，+匹配一个或多个
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkRows(0)
+        
+        sql = sql.replace('limit','slimit')
+        self.sql_query_time_cost(sql)
+        tdSql.checkRows(num*per_table_num)
+        nest_sql = nest_sql.replace('limit','slimit')
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkRows(num*per_table_num)
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkRows(0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkRows(0)
+
+    def sql_data_limit_retun_tables_times_n_slimit_return_per_table_num_times_n(self,sql,num,tables,per_table_num,base_fun,replace_fun): 
+        #sql limit n =n*tables;sql limit 0 = 0 ;sql slmit n = per_table_num*n;sql slimit 0  = 0   
+        #interval   
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+         
+        nest_sql =" select * from (%s) " %sql     
+        self.sql_query_time_cost(sql)
+        tdSql.checkData(0,0,num*tables)
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkData(0,0,num*tables) 
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkData(0,0,0)
+        
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql) # \d是匹配数字字符[0-9]，+匹配一个或多个
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkData(0,0,0)
+        
+        sql = sql.replace('limit','slimit')
+        self.sql_query_time_cost(sql)
+        tdSql.checkData(0,0,num*per_table_num)
+        nest_sql = nest_sql.replace('limit','slimit')
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkData(0,0,num*per_table_num)
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkData(0,0,0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkData(0,0,0)
+
+    def sql_limit_retun_n_slimit_return_per_table_num_times_tables(self,sql,num,tables,per_table_num,base_fun,replace_fun): 
+        #sql limit n =n*tables;sql limit 0 = 0 ;sql slmit n = per_table_num*n;sql slimit 0  = 0   
+        #interval  
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+         
+        nest_sql =" select * from (%s) " %sql     
+        self.sql_query_time_cost(sql)
+        tdSql.checkRows(num)
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkRows(num) 
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkRows(0)
+        
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql) # \d是匹配数字字符[0-9]，+匹配一个或多个
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkRows(0)
+        
+        sql = sql.replace('limit','slimit')
+        self.sql_query_time_cost(sql)
+        tdSql.checkRows(tables*per_table_num)
+        nest_sql = nest_sql.replace('limit','slimit')
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkRows(tables*per_table_num)
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkRows(0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkRows(0)
+
+    def sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(self,sql,num,tables,per_table_num,base_fun,replace_fun): 
+        #sql limit n =n*tables;sql limit 0 = 0 ;sql slmit n = per_table_num*n;sql slimit 0  = 0   
+        #interval  
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+         
+        nest_sql =" select * from (%s) " %sql     
+        self.sql_query_time_cost(sql)
+        tdSql.checkData(0,0,num)
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkData(0,0,num) 
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkData(0,0,0)
+        
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql) # \d是匹配数字字符[0-9]，+匹配一个或多个
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkData(0,0,0)
+        
+        sql = sql.replace('limit','slimit')
+        self.sql_query_time_cost(sql)
+        tdSql.checkData(0,0,tables*per_table_num)
+        nest_sql = nest_sql.replace('limit','slimit')
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkData(0,0,tables*per_table_num)
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkData(0,0,0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkData(0,0,0)
+
+    def sql_limit_not_test_slimitkeep_return_per_table_num_times_n(self,sql,num,tables,per_table_num,base_fun,replace_fun): 
+        #sql sql slmit n = per_table_num*n;sql slimit 0  = 0 
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+         
+        nest_sql =" select * from (%s) " %sql                
+        sql = sql.replace('limit','limit')
+        self.sql_query_time_cost(sql)
+        tdSql.checkRows(num*per_table_num)
+        
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkRows(num*per_table_num)
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkRows(0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkRows(0)
+
+    def sql_data_limit_not_test_slimitkeep_return_per_table_num_times_n(self,sql,num,tables,per_table_num,base_fun,replace_fun): 
+        #sql sql slmit n = per_table_num*n;sql slimit 0  = 0 
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+         
+        nest_sql =" select * from (%s) " %sql                
+        sql = sql.replace('limit','limit')
+        self.sql_query_time_cost(sql)
+        tdSql.checkData(0,0,num*per_table_num)
+        
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkData(0,0,num*per_table_num)
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkData(0,0,0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkData(0,0,0)
+
+    def sql_limit_not_test_slimitkeep_return_per_table_num_times_tables(self,sql,num,tables,per_table_num,base_fun,replace_fun): 
+        #sql sql slmit n = per_table_num*tables;sql slimit 0  = 0   
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+         
+        nest_sql =" select * from (%s) " %sql         
+        self.sql_query_time_cost(sql)
+        tdSql.checkRows(tables*per_table_num)
+        
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkRows(tables*per_table_num)
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkRows(0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkRows(0)
+
+    def sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(self,sql,num,tables,per_table_num,base_fun,replace_fun): 
+        #sql sql slmit n = per_table_num*tables;sql slimit 0  = 0   
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+         
+        nest_sql =" select * from (%s) " %sql         
+        self.sql_query_time_cost(sql)
+        tdSql.checkData(0,0,tables*per_table_num)
+        
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkData(0,0,tables*per_table_num)
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkData(0,0,0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkData(0,0,0)
+        
+    def sql_limit_retun_n_times_n2_slimitkeep_return_n_times_n2(self,sql,num,num2,tables,per_table_num,base_fun,replace_fun): 
+        #sql limit n =n*num2;sql limit 0 = 0 ;sql slmit n = num2*n;sql slimit 0  = 0 
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+         
+        nest_sql =" select * from (%s) " %sql            
+        self.sql_query_time_cost(sql)
+        tdSql.checkRows(num*num2)        
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkRows(num*num2)
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkRows(0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkRows(0)
+        
+        sql = sql.replace('limit','limit')
+        self.sql_query_time_cost(sql)
+        tdSql.checkRows(num*num2)   
+        nest_sql = nest_sql.replace('limit','limit')  
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkRows(num*num2)
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkRows(0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkRows(0)
+        
+    def sql_data_limit_retun_n_times_n2_slimitkeep_return_n_times_n2(self,sql,num,num2,tables,per_table_num,base_fun,replace_fun): 
+        #sql limit n =n*num2;sql limit 0 = 0 ;sql slmit n = num2*n;sql slimit 0  = 0 
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+         
+        nest_sql =" select * from (%s) " %sql            
+        self.sql_query_time_cost(sql)
+        tdSql.checkData(0,0,num*num2)        
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkData(0,0,num*num2)
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkData(0,0,0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkData(0,0,0)
+        
+        sql = sql.replace('limit','limit')
+        self.sql_query_time_cost(sql)
+        tdSql.checkData(0,0,num*num2)   
+        nest_sql = nest_sql.replace('limit','limit')  
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkData(0,0,num*num2)
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkData(0,0,0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkData(0,0,0)
+        
+    def sql_limit_times_slimitkeep_return_n2(self,sql,num,num2,tables,per_table_num,base_fun,replace_fun): 
+        #sql limit n =n*num2;sql limit 0 = 0 ;sql slmit n = num2*n;sql slimit 0  = 0   
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+         
+        nest_sql =" select * from (%s) " %sql     
+        self.sql_query_time_cost(sql)
+        tdSql.checkRows(num2)      
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkRows(num2)
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkRows(0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkRows(0)
+        
+    def sql_data_limit_times_slimitkeep_return_n2(self,sql,num,num2,tables,per_table_num,base_fun,replace_fun): 
+        #sql limit n =n*num2;sql limit 0 = 0 ;sql slmit n = num2*n;sql slimit 0  = 0   
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+         
+        nest_sql =" select * from (%s) " %sql     
+        self.sql_query_time_cost(sql)
+        tdSql.checkData(0,0,num2)      
+        self.sql_query_time_cost(nest_sql)
+        tdSql.checkData(0,0,num2)
+        
+        sql_0 = re.sub(r'\d\d',"0",sql)
+        self.sql_query_time_cost(sql_0)
+        tdSql.checkData(0,0,0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        self.sql_query_time_cost(nest_sql_0)
+        tdSql.checkData(0,0,0)
+
+    def sql_retun_error(self,sql,base_fun,replace_fun): 
+        #sql limit n = error;sql limit 0 = error ;sql slmit n = error ;sql slimit 0 = error 
+        sql = sql.replace('%s'%base_fun,'%s'%replace_fun)
+          
+        nest_sql =" select * from (%s) " %sql            
+        tdSql.error(sql)
+        tdSql.error(nest_sql)
+        
+        sql_0 = re.sub(r'\d+',"0",sql)
+        tdSql.error(sql)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        tdSql.error(nest_sql_0)
+        
+        sql = sql.replace('limit','slimit')
+        tdSql.error(sql)
+        nest_sql = nest_sql.replace('limit','slimit')
+        tdSql.error(nest_sql)
+        
+        sql_0 = re.sub(r'\d+',"0",sql)
+        tdSql.error(sql_0)
+        nest_sql_0 = re.sub(r'\d\d',"0",nest_sql)
+        tdSql.error(nest_sql_0)
+
+    def fun_base(self,dbname,num,num2,tables,per_table_num,dbnamejoin,base_fun,replace_fun):
+        
+        tdLog.info("base query ---------1----------")
+        sql = "select * from %s.meters limit %d" %(dbname,num)
+        self.sql_limit_retun_n_slimit_return_error(sql,num,tables,per_table_num,base_fun,replace_fun)        
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_n_slimit_return_error(sql,num,tables,per_table_num,base_fun,replace_fun)  
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select a.* from %s.meters a,%s.meters b where a.ts = b.ts limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_n_slimit_return_error(sql_join,num,tables,per_table_num,base_fun,replace_fun)  
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_n_slimit_return_error(sql_join,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        
+        tdLog.info("base query ---------2----------")
+        sql = "select * from %s.meters where ts is not null limit %d" %(dbname,num)
+        self.sql_limit_retun_n_slimit_return_error(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_n_slimit_return_error(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select a.* from %s.meters a,%s.meters b where a.ts is not null and  a.ts = b.ts limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_n_slimit_return_error(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_n_slimit_return_error(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        
+        tdLog.info("base query ---------3----------")
+        sql = "select * from %s.meters where ts is not null order by ts limit %d" %(dbname,num)
+        self.sql_limit_retun_n_slimit_return_error(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_n_slimit_return_error(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select a.* from %s.meters a,%s.meters b where a.ts is not null  and  a.ts = b.ts order by b.ts limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_n_slimit_return_error(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_n_slimit_return_error(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        tdLog.info("base query ---------4----------")
+        sql = "select * from %s.meters where ts is not null order by ts desc limit %d" %(dbname,num)
+        self.sql_limit_retun_n_slimit_return_error(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_n_slimit_return_error(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+               
+        sql_join = "select a.* from %s.meters a,%s.meters b where b.ts is not null and  a.ts = b.ts order by a.ts desc limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_n_slimit_return_error(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_n_slimit_return_error(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+    
+    def fun_count(self,dbname,num,num2,tables,per_table_num,dbnamejoin,base_fun,replace_fun):
+        
+        tdLog.info("count query ---------1----------")       
+        sql = "select count(*) from %s.meters limit %d" %(dbname,num)
+        self.sql_limit_retun_1_slimit_return_error(sql,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_1_slimit_return_error(sql,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_1_slimit_return_error(sql_union,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_1_slimit_return_error(sql_union_all,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select count(a.*) from %s.meters a,%s.meters b where a.ts = b.ts limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_1_slimit_return_error(sql_join,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_1_slimit_return_error(sql_join,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_1_slimit_return_error(sql_union,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_1_slimit_return_error(sql_union_all,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        
+        
+        tdLog.info("count query ---------2----------")
+        sql = "select count(*) from %s.meters where ts is not null limit %d" %(dbname,num)
+        self.sql_limit_retun_1_slimit_return_error(sql,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_1_slimit_return_error(sql,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_1_slimit_return_error(sql_union,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_1_slimit_return_error(sql_union_all,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select count(a.*) from %s.meters a,%s.meters b where a.ts is not null and  a.ts = b.ts limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_1_slimit_return_error(sql_join,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_1_slimit_return_error(sql_join,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_1_slimit_return_error(sql_union,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_1_slimit_return_error(sql_union_all,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        
+        tdLog.info("count query ---------3----------")
+        sql = "select count(*) from %s.meters where ts is not null order by ts limit %d" %(dbname,num)
+        self.sql_retun_error(sql,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_retun_error(sql,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_retun_error(sql_union,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_retun_error(sql_union_all,base_fun,replace_fun)
+        
+        sql_join = "select count(a.*) from %s.meters a,%s.meters b where a.ts is not null and  a.ts = b.ts order by b.ts limit %d" %(dbname,dbnamejoin,num)
+        self.sql_retun_error(sql_join,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_retun_error(sql_join,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_retun_error(sql_union,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_retun_error(sql_union_all,base_fun,replace_fun)
+        
+        
+        
+        tdLog.info("count query ---------4----------")
+        sql = "select count(*) from %s.meters where ts is not null order by ts desc limit %d" %(dbname,num)        
+        self.sql_retun_error(sql,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_retun_error(sql,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_retun_error(sql_union,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_retun_error(sql_union_all,base_fun,replace_fun)
+        
+        sql_join = "select count(a.*) from %s.meters a,%s.meters b where b.ts is not null and  a.ts = b.ts order by a.ts desc limit %d" %(dbname,dbnamejoin,num)        
+        self.sql_retun_error(sql_join,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_retun_error(sql_join,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_retun_error(sql_union,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_retun_error(sql_union_all,base_fun,replace_fun)
+        
+        
+        
+        tdLog.info("count query ---------5----------")
+        sql = "select count(*) from %s.meters where ts is not null group by tbname limit %d" %(dbname,num)
+        self.sql_limit_retun_tables_slimit_return_n(sql,num,tables,per_table_num,base_fun,replace_fun)        
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_tables_slimit_return_n(sql,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_tables_slimit_return_n(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_tables_slimit_return_n(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        sql_join = "select count(*) from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts group by b.tbname limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_tables_slimit_return_n(sql_join,num,tables,per_table_num,base_fun,replace_fun)        
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_tables_slimit_return_n(sql_join,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_tables_slimit_return_n(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_tables_slimit_return_n(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        
+        
+        
+        tdLog.info("count query ---------6----------")
+        sql = "select count(*) from %s.meters where ts is not null partition by tbname limit %d" %(dbname,num)
+        self.sql_limit_retun_tables_slimit_return_n(sql,num,tables,per_table_num,base_fun,replace_fun) 
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_tables_slimit_return_n(sql,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_tables_slimit_return_n(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_tables_slimit_return_n(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        sql_join = "select count(*) from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts partition by b.tbname limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_tables_slimit_return_n(sql_join,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_tables_slimit_return_n(sql_join,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_tables_slimit_return_n(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_tables_slimit_return_n(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        
+        
+        tdLog.info("count query ---------7----------")
+        sql = "select count(*) cc from %s.meters where ts is not null group by tbname order by cc limit %d" %(dbname,num)
+        self.sql_limit_retun_n_slimit_return_tables(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_n_slimit_return_tables(sql,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_n_slimit_return_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        sql_join  = "select count(*) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts group by b.tbname order by cc limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_n_slimit_return_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_n_slimit_return_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_n_slimit_return_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        
+        
+        tdLog.info("count query ---------8----------")
+        sql = "select count(*) cc from %s.meters where ts is not null partition by tbname order by cc limit %d" %(dbname,num)
+        self.sql_limit_retun_n_slimit_return_tables(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_n_slimit_return_tables(sql,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_n_slimit_return_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        sql_join = "select count(*) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts partition by b.tbname order by cc limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_n_slimit_return_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_n_slimit_return_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_n_slimit_return_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        
+        
+        tdLog.info("count query ---------9----------")
+        sql = "select count(*) cc from %s.meters where ts is not null interval(1a) limit %d" %(dbname,num)
+        self.sql_limit_retun_n_slimit_return_error(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_n_slimit_return_error(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        sql_join  = "select count(*) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts interval(1a) limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_n_slimit_return_error(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_n_slimit_return_error(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        
+        
+        tdLog.info("count query ---------10----------")
+        sql = "select count(*) cc from %s.meters where ts is not null interval(1a) order by cc asc limit %d" %(dbname,num)
+        self.sql_limit_retun_n_slimit_return_error(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_n_slimit_return_error(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        sql_join = "select count(*) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts interval(1a) order by cc asc limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_n_slimit_return_error(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_n_slimit_return_error(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        
+        
+        tdLog.info("count query ---------11----------")
+        sql = "select count(*) cc from %s.meters where ts is not null interval(1a) order by cc desc limit %d" %(dbname,num)
+        self.sql_limit_retun_n_slimit_return_error(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_n_slimit_return_error(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        sql_join = "select count(*) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts interval(1a) order by cc desc limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_n_slimit_return_error(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_n_slimit_return_error(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        
+        
+        tdLog.info("count query ---------12----------")
+        sql = "select tbname,count(*) cc from %s.meters where ts is not null interval(1a) group by tbname limit %d" %(dbname,num)
+        self.sql_retun_error(sql,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_retun_error(sql,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_retun_error(sql_union,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_retun_error(sql_union_all,base_fun,replace_fun)
+        
+        sql_join = "select a.tbname,count(*) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts interval(1a) group by b.tbname limit %d" %(dbname,dbnamejoin,num)
+        self.sql_retun_error(sql_join,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_retun_error(sql_join,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_retun_error(sql_union,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_retun_error(sql_union_all,base_fun,replace_fun)
+        
+        
+        
+        tdLog.info("count query ---------13----------")
+        sql = "select tbname,count(*) cc from %s.meters where ts is not null interval(1a) partition by tbname limit %d" %(dbname,num)
+        self.sql_retun_error(sql,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_retun_error(sql,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_retun_error(sql_union,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_retun_error(sql_union_all,base_fun,replace_fun)
+        
+        sql_join = "select a.tbname,count(*) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts interval(1a) partition by b.tbname limit %d" %(dbname,dbnamejoin,num)
+        self.sql_retun_error(sql_join,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_retun_error(sql_join,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_retun_error(sql_union,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_retun_error(sql_union_all,base_fun,replace_fun)
+        
+        
+        
+        tdLog.info("count query ---------14----------")
+        sql = "select tbname,count(*) cc from %s.meters where ts is not null partition by tbname interval(1a) limit %d" %(dbname,num)
+        self.sql_limit_retun_tables_times_n_slimit_return_per_table_num_times_n(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_tables_times_n_slimit_return_per_table_num_times_n(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_tables_times_n_slimit_return_per_table_num_times_n(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_tables_times_n_slimit_return_per_table_num_times_n(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select a.tbname,count(*) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts partition by a.tbname interval(1a) limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_tables_times_n_slimit_return_per_table_num_times_n(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_tables_times_n_slimit_return_per_table_num_times_n(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_tables_times_n_slimit_return_per_table_num_times_n(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_tables_times_n_slimit_return_per_table_num_times_n(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        
+        tdLog.info("count query ---------15----------")
+        sql = "select tbname,count(*) cc from %s.meters where ts is not null partition by tbname interval(1a) order by cc asc limit %d" %(dbname,num)
+        self.sql_limit_retun_n_slimit_return_per_table_num_times_tables(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select a.tbname,count(*) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts partition by a.tbname interval(1a) order by cc asc limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_n_slimit_return_per_table_num_times_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        
+        tdLog.info("count query ---------16----------")
+        sql = "select tbname,count(*) cc from %s.meters where ts is not null partition by tbname interval(1a) order by cc desc limit %d" %(dbname,num)
+        self.sql_limit_retun_n_slimit_return_per_table_num_times_tables(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select a.tbname,count(*) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts partition by a.tbname interval(1a) order by cc desc limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_n_slimit_return_per_table_num_times_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        
+        tdLog.info("count query ---------17----------")
+        sql = "select tbname,count(*) cc from %s.meters where ts is not null partition by tbname interval(1a) slimit %d" %(dbname,num)
+        self.sql_limit_not_test_slimitkeep_return_per_table_num_times_n(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_n(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_n(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_n(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select a.tbname,count(*) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts partition by a.tbname interval(1a) slimit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_not_test_slimitkeep_return_per_table_num_times_n(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_n(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_n(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_n(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        
+        tdLog.info("count query ---------18----------")
+        sql = "select tbname,count(*) cc from %s.meters where ts is not null partition by tbname interval(1a) order by cc asc slimit %d" %(dbname,num)
+        self.sql_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select a.tbname,count(*) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts partition by a.tbname interval(1a) order by cc asc slimit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        tdLog.info("count query ---------19----------")
+        sql = "select tbname,count(*) cc from %s.meters where ts is not null partition by tbname interval(1a) order by cc desc slimit %d" %(dbname,num)
+        self.sql_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select a.tbname,count(*) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts partition by a.tbname interval(1a) order by cc desc slimit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        
+        tdLog.info("count query ---------20----------")
+        sql = "select tbname,count(*) cc from %s.meters where ts is not null partition by tbname interval(1a) slimit %d limit %d" %(dbname,num,num2)
+        self.sql_limit_retun_n_times_n2_slimitkeep_return_n_times_n2(sql,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_n_times_n2_slimitkeep_return_n_times_n2(sql,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_n_times_n2_slimitkeep_return_n_times_n2(sql_union,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_n_times_n2_slimitkeep_return_n_times_n2(sql_union_all,num,num2,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select a.tbname,count(*) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts partition by a.tbname interval(1a) slimit %d limit %d" %(dbname,dbnamejoin,num,num2)
+        self.sql_limit_retun_n_times_n2_slimitkeep_return_n_times_n2(sql_join,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_n_times_n2_slimitkeep_return_n_times_n2(sql_join,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_n_times_n2_slimitkeep_return_n_times_n2(sql_union,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_n_times_n2_slimitkeep_return_n_times_n2(sql_union_all,num,num2,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        tdLog.info("count query ---------21----------")
+        sql = "select tbname,count(*) cc from %s.meters where ts is not null partition by tbname interval(1a) order by cc asc slimit %d limit %d" %(dbname,num,num2)
+        self.sql_limit_times_slimitkeep_return_n2(sql,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_times_slimitkeep_return_n2(sql,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_times_slimitkeep_return_n2(sql_union,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_times_slimitkeep_return_n2(sql_union_all,num,num2,tables,per_table_num,base_fun,replace_fun)       
+        
+        sql_join = "select a.tbname,count(*) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts partition by a.tbname interval(1a) order by cc asc slimit %d limit %d" %(dbname,dbnamejoin,num,num2)
+        self.sql_limit_times_slimitkeep_return_n2(sql_join,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_times_slimitkeep_return_n2(sql_join,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_times_slimitkeep_return_n2(sql_union,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_times_slimitkeep_return_n2(sql_union_all,num,num2,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        tdLog.info("count query ---------22----------")
+        sql = "select tbname,count(*) cc from %s.meters where ts is not null partition by tbname interval(1a) order by cc desc slimit %d limit %d" %(dbname,num,num2)
+        self.sql_limit_times_slimitkeep_return_n2(sql,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_times_slimitkeep_return_n2(sql,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_times_slimitkeep_return_n2(sql_union,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_times_slimitkeep_return_n2(sql_union_all,num,num2,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select a.tbname,count(*) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts partition by a.tbname interval(1a) order by cc desc slimit %d limit %d" %(dbname,dbnamejoin,num,num2)
+        self.sql_limit_times_slimitkeep_return_n2(sql_join,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_times_slimitkeep_return_n2(sql_join,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_times_slimitkeep_return_n2(sql_union,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_times_slimitkeep_return_n2(sql_union_all,num,num2,tables,per_table_num,base_fun,replace_fun)
+        
+         
+    def fun_last(self,dbname,num,num2,tables,per_table_num,dbnamejoin,base_fun,replace_fun):
+        
+        tdLog.info("last query ---------1----------")       
+        sql = "select last(*) from %s.meters limit %d" %(dbname,num)
+        self.sql_limit_retun_1_slimit_return_error(sql,tables,per_table_num,base_fun,replace_fun)
+        sql = "select last(*) from (%s)" %sql
+        self.sql_limit_retun_1_slimit_return_error(sql,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_last_limit_retun_1_slimit_return_error(sql_union,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_last_limit_retun_1_slimit_return_error(sql_union_all,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select last(a.*) from %s.meters a,%s.meters b where a.ts = b.ts limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_1_slimit_return_error(sql_join,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select last(*) from (%s)" %sql_join
+        self.sql_limit_retun_1_slimit_return_error(sql_join,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_last_limit_retun_1_slimit_return_error(sql_union,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_last_limit_retun_1_slimit_return_error(sql_union_all,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        
+        
+        tdLog.info("last query ---------2----------")
+        sql = "select last(*) from %s.meters where ts is not null limit %d" %(dbname,num)
+        self.sql_limit_retun_1_slimit_return_error(sql,tables,per_table_num,base_fun,replace_fun)
+        sql = "select last(*) from (%s)" %sql
+        self.sql_limit_retun_1_slimit_return_error(sql,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_last_limit_retun_1_slimit_return_error(sql_union,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_last_limit_retun_1_slimit_return_error(sql_union_all,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select last(a.*) from %s.meters a,%s.meters b where a.ts is not null and  a.ts = b.ts limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_1_slimit_return_error(sql_join,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select last(*) from (%s)" %sql_join
+        self.sql_limit_retun_1_slimit_return_error(sql_join,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_last_limit_retun_1_slimit_return_error(sql_union,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_last_limit_retun_1_slimit_return_error(sql_union_all,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        
+        tdLog.info("last query ---------3----------")
+        sql = "select last(*) from %s.meters where ts is not null order by ts limit %d" %(dbname,num)
+        self.sql_retun_error(sql,base_fun,replace_fun)
+        sql = "select last(*) from (%s)" %sql
+        self.sql_retun_error(sql,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_retun_error(sql_union,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_retun_error(sql_union_all,base_fun,replace_fun)
+        
+        sql_join = "select last(a.*) from %s.meters a,%s.meters b where a.ts is not null and  a.ts = b.ts order by b.ts limit %d" %(dbname,dbnamejoin,num)
+        self.sql_retun_error(sql_join,base_fun,replace_fun)
+        sql_join = "select last(*) from (%s)" %sql_join
+        self.sql_retun_error(sql_join,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_retun_error(sql_union,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_retun_error(sql_union_all,base_fun,replace_fun)
+        
+        
+        
+        tdLog.info("last query ---------4----------")
+        sql = "select last(*) from %s.meters where ts is not null order by ts desc limit %d" %(dbname,num)        
+        self.sql_retun_error(sql,base_fun,replace_fun)
+        sql = "select last(*) from (%s)" %sql
+        self.sql_retun_error(sql,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_retun_error(sql_union,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_retun_error(sql_union_all,base_fun,replace_fun)
+        
+        sql_join = "select last(a.*) from %s.meters a,%s.meters b where b.ts is not null and  a.ts = b.ts order by a.ts desc limit %d" %(dbname,dbnamejoin,num)        
+        self.sql_retun_error(sql_join,base_fun,replace_fun)
+        sql_join = "select last(*) from (%s)" %sql_join
+        self.sql_retun_error(sql_join,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_retun_error(sql_union,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_retun_error(sql_union_all,base_fun,replace_fun)
+        
+        
+        
+        tdLog.info("last query ---------5----------")
+        sql = "select last(*) from %s.meters where ts is not null group by tbname limit %d" %(dbname,num)
+        self.sql_limit_retun_tables_slimit_return_n(sql,num,tables,per_table_num,base_fun,replace_fun)        
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_tables_slimit_return_n(sql,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_tables_slimit_return_n(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_tables_slimit_return_n(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        sql_join = "select last(a.*) from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts group by b.tbname limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_tables_slimit_return_n(sql_join,num,tables,per_table_num,base_fun,replace_fun)        
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_tables_slimit_return_n(sql_join,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_tables_slimit_return_n(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_tables_slimit_return_n(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        
+        
+        
+        tdLog.info("last query ---------6----------")
+        sql = "select last(*) from %s.meters where ts is not null partition by tbname limit %d" %(dbname,num)
+        self.sql_limit_retun_tables_slimit_return_n(sql,num,tables,per_table_num,base_fun,replace_fun) 
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_tables_slimit_return_n(sql,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_tables_slimit_return_n(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_tables_slimit_return_n(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        sql_join = "select last(a.*) from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts partition by b.tbname limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_tables_slimit_return_n(sql_join,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_tables_slimit_return_n(sql_join,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_tables_slimit_return_n(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_tables_slimit_return_n(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        
+        
+        tdLog.info("last query ---------7----------")
+        sql = "select last(ts) cc from %s.meters where ts is not null group by tbname order by cc limit %d" %(dbname,num)
+        self.sql_limit_retun_n_slimit_return_tables(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_n_slimit_return_tables(sql,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_n_slimit_return_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        sql_join  = "select last(a.ts) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts group by b.tbname order by cc limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_n_slimit_return_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_n_slimit_return_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_n_slimit_return_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        
+        
+        tdLog.info("last query ---------8----------")
+        sql = "select last(ts) cc from %s.meters where ts is not null partition by tbname order by cc limit %d" %(dbname,num)
+        self.sql_limit_retun_n_slimit_return_tables(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_n_slimit_return_tables(sql,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_n_slimit_return_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        sql_join = "select last(a.ts) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts partition by b.tbname order by cc limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_n_slimit_return_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_n_slimit_return_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_n_slimit_return_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        
+        
+        tdLog.info("last query ---------9----------")
+        sql = "select last(*) from %s.meters where ts is not null interval(1a) limit %d" %(dbname,num)
+        self.sql_limit_retun_n_slimit_return_error(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_n_slimit_return_error(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        sql_join  = "select last(a.ts) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts interval(1a) limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_n_slimit_return_error(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_n_slimit_return_error(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        
+        
+        tdLog.info("last query ---------10----------")
+        sql = "select last(ts) cc from %s.meters where ts is not null interval(1a) order by cc asc limit %d" %(dbname,num)
+        self.sql_limit_retun_n_slimit_return_error(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_n_slimit_return_error(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        sql_join = "select last(a.ts) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts interval(1a) order by cc asc limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_n_slimit_return_error(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_n_slimit_return_error(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        
+        
+        tdLog.info("last query ---------11----------")
+        sql = "select last(ts) cc from %s.meters where ts is not null interval(1a) order by cc desc limit %d" %(dbname,num)
+        self.sql_limit_retun_n_slimit_return_error(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_n_slimit_return_error(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        sql_join = "select last(a.ts) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts interval(1a) order by cc desc limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_n_slimit_return_error(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_n_slimit_return_error(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union,num,tables,per_table_num,base_fun,replace_fun) 
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_error(sql_union_all,num,tables,per_table_num,base_fun,replace_fun) 
+        
+        
+        
+        tdLog.info("last query ---------12----------")
+        sql = "select tbname,last(ts) cc from %s.meters where ts is not null interval(1a) group by tbname limit %d" %(dbname,num)
+        self.sql_retun_error(sql,base_fun,replace_fun)
+        sql = "select last(*) from (%s)" %sql
+        self.sql_retun_error(sql,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_retun_error(sql_union,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_retun_error(sql_union_all,base_fun,replace_fun)
+        
+        sql_join = "select a.tbname,last(a.ts) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts interval(1a) group by b.tbname limit %d" %(dbname,dbnamejoin,num)
+        self.sql_retun_error(sql_join,base_fun,replace_fun)
+        sql_join = "select last(*) from (%s)" %sql_join
+        self.sql_retun_error(sql_join,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_retun_error(sql_union,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_retun_error(sql_union_all,base_fun,replace_fun)
+        
+        
+        
+        tdLog.info("last query ---------13----------")
+        sql = "select tbname,last(ts) cc from %s.meters where ts is not null interval(1a) partition by tbname limit %d" %(dbname,num)
+        self.sql_retun_error(sql,base_fun,replace_fun)
+        sql = "select last(*) from (%s)" %sql
+        self.sql_retun_error(sql,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_retun_error(sql_union,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_retun_error(sql_union_all,base_fun,replace_fun)
+        
+        sql_join = "select a.tbname,last(a.ts) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts interval(1a) partition by b.tbname limit %d" %(dbname,dbnamejoin,num)
+        self.sql_retun_error(sql_join,base_fun,replace_fun)
+        sql_join = "select last(*) from (%s)" %sql_join
+        self.sql_retun_error(sql_join,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_retun_error(sql_union,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_retun_error(sql_union_all,base_fun,replace_fun)
+        
+        
+        
+        tdLog.info("last query ---------14----------") 
+        sql = "select tbname,last(*) cc from %s.meters where ts is not null partition by tbname interval(1a) limit %d" %(dbname,num)
+        self.sql_limit_retun_tables_times_n_slimit_return_per_table_num_times_n(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_tables_times_n_slimit_return_per_table_num_times_n(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_tables_times_n_slimit_return_per_table_num_times_n(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_tables_times_n_slimit_return_per_table_num_times_n(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select a.tbname,last(a.ts) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts partition by a.tbname interval(1a) limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_tables_times_n_slimit_return_per_table_num_times_n(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_tables_times_n_slimit_return_per_table_num_times_n(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_tables_times_n_slimit_return_per_table_num_times_n(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_tables_times_n_slimit_return_per_table_num_times_n(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        
+        tdLog.info("last query ---------15----------")
+        sql = "select tbname,last(ts) cc from %s.meters where ts is not null partition by tbname interval(1a) order by cc asc limit %d" %(dbname,num)
+        self.sql_limit_retun_n_slimit_return_per_table_num_times_tables(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select a.tbname,last(a.ts) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts partition by a.tbname interval(1a) order by cc asc limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_n_slimit_return_per_table_num_times_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        
+        tdLog.info("last query ---------16----------")
+        sql = "select tbname,last(ts) cc from %s.meters where ts is not null partition by tbname interval(1a) order by cc desc limit %d" %(dbname,num)
+        self.sql_limit_retun_n_slimit_return_per_table_num_times_tables(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select a.tbname,last(a.ts) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts partition by a.tbname interval(1a) order by cc desc limit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_retun_n_slimit_return_per_table_num_times_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_n_slimit_return_per_table_num_times_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        
+        tdLog.info("last query ---------17----------")
+        sql = "select tbname,last(*) cc from %s.meters where ts is not null partition by tbname interval(1a) slimit %d" %(dbname,num)
+        self.sql_limit_not_test_slimitkeep_return_per_table_num_times_n(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_n(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_n(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_n(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select a.tbname,last(a.ts) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts partition by a.tbname interval(1a) slimit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_not_test_slimitkeep_return_per_table_num_times_n(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_n(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_n(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_n(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        
+        tdLog.info("last query ---------18----------")
+        sql = "select tbname,last(ts) cc from %s.meters where ts is not null partition by tbname interval(1a) order by cc asc slimit %d" %(dbname,num)
+        self.sql_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select a.tbname,last(a.ts) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts partition by a.tbname interval(1a) order by cc asc slimit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        tdLog.info("last query ---------19----------")
+        sql = "select tbname,last(ts) cc from %s.meters where ts is not null partition by tbname interval(1a) order by cc desc slimit %d" %(dbname,num)
+        self.sql_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select a.tbname,last(a.ts) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts partition by a.tbname interval(1a) order by cc desc slimit %d" %(dbname,dbnamejoin,num)
+        self.sql_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_join,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_union,num,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_not_test_slimitkeep_return_per_table_num_times_tables(sql_union_all,num,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        
+        tdLog.info("last query ---------20----------") 
+        sql = "select tbname,last(*) cc from %s.meters where ts is not null partition by tbname interval(1a) slimit %d limit %d" %(dbname,num,num2)
+        self.sql_limit_retun_n_times_n2_slimitkeep_return_n_times_n2(sql,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_retun_n_times_n2_slimitkeep_return_n_times_n2(sql,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_retun_n_times_n2_slimitkeep_return_n_times_n2(sql_union,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_retun_n_times_n2_slimitkeep_return_n_times_n2(sql_union_all,num,num2,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select a.tbname,last(a.*) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts partition by a.tbname interval(1a) slimit %d limit %d" %(dbname,dbnamejoin,num,num2)
+        self.sql_limit_retun_n_times_n2_slimitkeep_return_n_times_n2(sql_join,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_retun_n_times_n2_slimitkeep_return_n_times_n2(sql_join,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_retun_n_times_n2_slimitkeep_return_n_times_n2(sql_union,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_retun_n_times_n2_slimitkeep_return_n_times_n2(sql_union_all,num,num2,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        tdLog.info("last query ---------21----------")
+        sql = "select tbname,last(ts) cc from %s.meters where ts is not null partition by tbname interval(1a) order by cc asc slimit %d limit %d" %(dbname,num,num2)
+        self.sql_limit_times_slimitkeep_return_n2(sql,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_times_slimitkeep_return_n2(sql,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_times_slimitkeep_return_n2(sql_union,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_times_slimitkeep_return_n2(sql_union_all,num,num2,tables,per_table_num,base_fun,replace_fun)       
+        
+        sql_join = "select a.tbname,last(a.ts) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts partition by a.tbname interval(1a) order by cc asc slimit %d limit %d" %(dbname,dbnamejoin,num,num2)
+        self.sql_limit_times_slimitkeep_return_n2(sql_join,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_times_slimitkeep_return_n2(sql_join,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_times_slimitkeep_return_n2(sql_union,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_times_slimitkeep_return_n2(sql_union_all,num,num2,tables,per_table_num,base_fun,replace_fun)
+        
+        
+        tdLog.info("last query ---------22----------")
+        sql = "select tbname,last(ts) cc from %s.meters where ts is not null partition by tbname interval(1a) order by cc desc slimit %d limit %d" %(dbname,num,num2)
+        self.sql_limit_times_slimitkeep_return_n2(sql,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql = "select count(*) from (%s)" %sql
+        self.sql_data_limit_times_slimitkeep_return_n2(sql,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql,sql)
+        self.sql_data_limit_times_slimitkeep_return_n2(sql_union,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql,sql_union)
+        self.sql_data_limit_times_slimitkeep_return_n2(sql_union_all,num,num2,tables,per_table_num,base_fun,replace_fun)
+        
+        sql_join = "select a.tbname,last(a.ts) cc from %s.meters a,%s.meters b where a.ts is not null and a.ts = b.ts partition by a.tbname interval(1a) order by cc desc slimit %d limit %d" %(dbname,dbnamejoin,num,num2)
+        self.sql_limit_times_slimitkeep_return_n2(sql_join,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_join = "select count(*) from (%s)" %sql_join
+        self.sql_data_limit_times_slimitkeep_return_n2(sql_join,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union = "(%s) union (%s)" %(sql_join,sql_join)
+        self.sql_data_limit_times_slimitkeep_return_n2(sql_union,num,num2,tables,per_table_num,base_fun,replace_fun)
+        sql_union_all = "(%s) union all (%s)" %(sql_join,sql_union)
+        self.sql_data_limit_times_slimitkeep_return_n2(sql_union_all,num,num2,tables,per_table_num,base_fun,replace_fun)
+        
+        
+            
+   
+
+    def sql_base_check(self,sql1,sql2):
+        tdSql.query(sql1)
+        sql1_result = tdSql.getData(0,0)
+        tdLog.info("sql:%s , result: %s" %(sql1,sql1_result))
+
+        tdSql.query(sql2)
+        sql2_result = tdSql.getData(0,0)
+        tdLog.info("sql:%s , result: %s" %(sql2,sql2_result))
+
+        if sql1_result==sql2_result:
+            tdLog.info(f"checkEqual success, sql1_result={sql1_result},sql2_result={sql2_result}")
+        else :
+            tdLog.exit(f"checkEqual error, sql1_result=={sql1_result},sql2_result={sql2_result}")
+
+    def run_limit_slimit_sql(self,dbname,tables,per_table_num,dbnamejoin):
+        
+        num,num2 = random.randint(10,100),random.randint(10,100)
+        self.sql_base(dbname,num,num2,tables,per_table_num,dbnamejoin)
+
+        tdSql.execute(" flush database %s;" %dbname)
+
+        self.sql_base(dbname,num,num2,tables,per_table_num,dbnamejoin)
+
+    def check_sub(self,dbname):
+
+        sql = "select count(*) from (select distinct(tbname) from %s.meters)" %dbname
+        self.sql_query_time_cost(sql)
+        num = tdSql.getData(0,0)
+
+        for i in range(0,num):
+            sql1 = "select count(*) from %s.d%d" %(dbname,i)
+            self.sql_query_time_cost(sql1)
+            sql1_result = tdSql.getData(0,0)
+            tdLog.info("sql:%s , result: %s" %(sql1,sql1_result))
+    
+                
+    def sql_base(self,dbname,num,num2,tables,per_table_num,dbnamejoin):
+        
+        sql = "select count(*) from %s.meters" %dbname
+        self.sql_query_time_cost(sql)
+        tdSql.checkData(0,0,tables*per_table_num)
+        sql = "select count(*) from %s.meters" %dbnamejoin
+        self.sql_query_time_cost(sql)
+        
+        self.fun_base(dbname,num,num2,tables,per_table_num,dbnamejoin,'*','*')
+        # self.fun_count(dbname,num,num2,tables,per_table_num,dbnamejoin,'count','count')
+        # self.fun_last(dbname,num,num2,tables,per_table_num,dbnamejoin,'last','last')
+        # #self.fun_last(dbname,num,num2,tables,per_table_num,dbnamejoin,'last','last_row')
+        # self.fun_last(dbname,num,num2,tables,per_table_num,dbnamejoin,'last','first')
+            
+    def test(self,dbname,tables,per_table_num,vgroups,replica,dbnamejoin):
+        self.run_benchmark(dbname,tables,per_table_num,vgroups,replica)
+        self.run_benchmark(dbnamejoin,tables,per_table_num,vgroups,replica)
+        self.run_limit_slimit_sql(dbname,tables,per_table_num,dbnamejoin)
+
+    def run(self):
+        startTime = time.time()
+
+        dbname = 'test'
+        dbnamejoin = 'testjoin'
+        vgroups = random.randint(1,8)
+        tables = random.randint(100,300)
+        per_table_num = random.randint(100,500)
+        replica = 1
+        #self.test('test',tables,per_table_num,vgroup,1) 
+        #self.test('test',10000,150,vgroup,1)     
+        
+        self.test('test',100,150,vgroups,1,'testjoin')    #方便调试，调试时不执行下面3个 
+        
+        # self.run_benchmark(dbname,tables,per_table_num,vgroups,replica)
+        # self.run_benchmark(dbnamejoin,tables*vgroups,per_table_num*vgroups,vgroups*2,replica) #方便测试不同数据量
+        # self.run_limit_slimit_sql(dbname,tables,per_table_num,dbnamejoin)  
+
+        endTime = time.time()
+        print("total time %ds" % (endTime - startTime))
+
+
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())