Fix quirk of isolation2 test (#8245)

* Fix quirk of isolation2 test

- Fix the line continuation behaviour and document
Instead of matching "; *$" to detect the end of a sql end, the original
code was using ";$". This creates a totally different output for tests
like:
a)
SELECT * FROM t1;
SELECT * FROM t2;
b)
SELECT * FROM t1;<space>
SELECT * FROM t2;
For a), two SELECT statements will be sent separately.
For b), they will be sent together as
        "SELECT * FROM t1; SELECT * FROM t2;"

Spaces are playing too much magic here, some of them could be a bug in
the test itself. For example, the oom_query test should NOT pass since
it misses error output in the expected.

This change unifies the behaviours by matching with "; *$". So if a line
is end with ';', no matter spaces follows it or not, the statement will
be sent at once.

- Document the known issue of multi SQL in one line.

This issue was found during debugging pipeline failure of #8211
Authored-by: NChen Mulong <muchen@pivotal.io>

src/test/isolation2/expected/dml_on_root_locks_all_parts.out

@@ -49,7 +49,9 @@ DELETE 0
 1: BEGIN;
 BEGIN
 -- UPDATE will acquire Exclusive lock on root and leaf partition on QD.
-1: UPDATE part_tbl SET c = 1; SELECT GRANTED FROM pg_locks WHERE relation = 'part_tbl_1_prt_1'::regclass::oid AND mode='ExclusiveLock' AND gp_segment_id=-1 AND locktype='relation';
+1: UPDATE part_tbl SET c = 1;
+UPDATE 0
+SELECT GRANTED FROM pg_locks WHERE relation = 'part_tbl_1_prt_1'::regclass::oid AND mode='ExclusiveLock' AND gp_segment_id=-1 AND locktype='relation';
  granted 
 ---------
  t       

src/test/isolation2/expected/oom_query.out

-SELECT Count(*) FROM   (SELECT l0.l_partkey FROM   (lineitem l0 LEFT OUTER JOIN lineitem l1 ON l0.l_partkey = l1.l_partkey LEFT OUTER JOIN lineitem l2 ON l1.l_partkey = l2.l_partkey LEFT OUTER JOIN lineitem l3 ON l2.l_partkey = l3.l_partkey LEFT OUTER JOIN lineitem l4 ON l3.l_partkey = l4.l_partkey LEFT OUTER JOIN lineitem l5 ON l4.l_partkey = l5.l_partkey LEFT OUTER JOIN lineitem l6 ON l5.l_partkey = l6.l_partkey LEFT OUTER JOIN lineitem l7 ON l6.l_partkey = l7.l_partkey LEFT OUTER JOIN lineitem l8 ON l7.l_partkey = l8.l_partkey LEFT OUTER JOIN lineitem l9 ON l8.l_partkey = l9.l_partkey LEFT OUTER JOIN lineitem l10 ON l9.l_partkey = l10.l_partkey LEFT OUTER JOIN lineitem l11 ON l10.l_partkey = l11.l_partkey LEFT OUTER JOIN lineitem l12 ON l11.l_partkey = l12.l_partkey LEFT OUTER JOIN lineitem l13 ON l12.l_partkey = l13.l_partkey LEFT OUTER JOIN lineitem l14 ON l13.l_partkey = l14.l_partkey LEFT OUTER JOIN lineitem l15 ON l14.l_partkey = l15.l_partkey) ORDER  BY l0.l_partkey) AS foo; 
+SELECT Count(*) FROM   (SELECT l0.l_partkey FROM   (lineitem l0 LEFT OUTER JOIN lineitem l1 ON l0.l_partkey = l1.l_partkey LEFT OUTER JOIN lineitem l2 ON l1.l_partkey = l2.l_partkey LEFT OUTER JOIN lineitem l3 ON l2.l_partkey = l3.l_partkey LEFT OUTER JOIN lineitem l4 ON l3.l_partkey = l4.l_partkey LEFT OUTER JOIN lineitem l5 ON l4.l_partkey = l5.l_partkey LEFT OUTER JOIN lineitem l6 ON l5.l_partkey = l6.l_partkey LEFT OUTER JOIN lineitem l7 ON l6.l_partkey = l7.l_partkey LEFT OUTER JOIN lineitem l8 ON l7.l_partkey = l8.l_partkey LEFT OUTER JOIN lineitem l9 ON l8.l_partkey = l9.l_partkey LEFT OUTER JOIN lineitem l10 ON l9.l_partkey = l10.l_partkey LEFT OUTER JOIN lineitem l11 ON l10.l_partkey = l11.l_partkey LEFT OUTER JOIN lineitem l12 ON l11.l_partkey = l12.l_partkey LEFT OUTER JOIN lineitem l13 ON l12.l_partkey = l13.l_partkey LEFT OUTER JOIN lineitem l14 ON l13.l_partkey = l14.l_partkey LEFT OUTER JOIN lineitem l15 ON l14.l_partkey = l15.l_partkey) ORDER  BY l0.l_partkey) AS foo;
+ERROR:  Out of memory  (seg0 slice17 127.0.0.1:25432 pid=29534)
+DETAIL:  Per-query VM protect limit reached: current limit is 2048 kB, requested 1048584 bytes, available 0 MB

src/test/isolation2/expected/reindex/createidx_while_reindex_idx_heap_bitmap.out

 DROP TABLE IF EXISTS reindex_crtab_heap_bitmap;
 DROP
 
-CREATE TABLE reindex_crtab_heap_bitmap (a INT); insert into reindex_crtab_heap_bitmap select generate_series(1,1000);
-CREATE 1000
+CREATE TABLE reindex_crtab_heap_bitmap (a INT);
+CREATE
+insert into reindex_crtab_heap_bitmap select generate_series(1,1000);
+INSERT 1000
 insert into reindex_crtab_heap_bitmap select generate_series(1,1000);
 INSERT 1000
 create index idx_reindex_crtab_heap_bitmap on reindex_crtab_heap_bitmap(a);

src/test/isolation2/expected/reindex/createidx_while_reindex_idx_heap_btree.out

 DROP TABLE IF EXISTS reindex_crtab_heap_btree;
 DROP
 
-CREATE TABLE reindex_crtab_heap_btree (a INT); insert into reindex_crtab_heap_btree select generate_series(1,1000);
-CREATE 1000
+CREATE TABLE reindex_crtab_heap_btree (a INT);
+CREATE
+insert into reindex_crtab_heap_btree select generate_series(1,1000);
+INSERT 1000
 insert into reindex_crtab_heap_btree select generate_series(1,1000);
 INSERT 1000
 create index idx_reindex_crtab_heap_btree on reindex_crtab_heap_btree(a);

src/test/isolation2/expected/reindex/reindextable_while_reindex_idx_heap_bitmap.out

 DROP TABLE IF EXISTS reindex_crtab_heap_bitmap;
 DROP
 
-CREATE TABLE reindex_crtab_heap_bitmap (a INT); insert into reindex_crtab_heap_bitmap select generate_series(1,1000);
-CREATE 1000
+CREATE TABLE reindex_crtab_heap_bitmap (a INT);
+CREATE
+insert into reindex_crtab_heap_bitmap select generate_series(1,1000);
+INSERT 1000
 insert into reindex_crtab_heap_bitmap select generate_series(1,1000);
 INSERT 1000
 create index idx_reindex_crtab_heap_bitmap on reindex_crtab_heap_bitmap USING BITMAP(a);

src/test/isolation2/expected/reindex/vacuum_while_reindex_heap_btree.out

 DROP TABLE IF EXISTS reindex_heap;
 DROP
 
-CREATE TABLE reindex_heap (a INT); insert into reindex_heap select generate_series(1,1000);
-CREATE 1000
+CREATE TABLE reindex_heap (a INT);
+CREATE
+insert into reindex_heap select generate_series(1,1000);
+INSERT 1000
 insert into reindex_heap select generate_series(1,1000);
 INSERT 1000
 create index idx_btree_reindex_heap on reindex_heap(a);

src/test/isolation2/expected/reindex/vacuum_while_reindex_heap_btree_toast.out

 DROP TABLE IF EXISTS reindex_toast_heap;
 DROP
 
-CREATE TABLE reindex_toast_heap (a text, b int); alter table reindex_toast_heap alter column a set storage external;
+CREATE TABLE reindex_toast_heap (a text, b int);
 CREATE
+alter table reindex_toast_heap alter column a set storage external;
+ALTER
 insert into reindex_toast_heap select repeat('123456789',10000), i from generate_series(1,100) i;
 INSERT 100
 create index idx_btree_reindex_toast_heap on reindex_toast_heap(b);

src/test/isolation2/sql/oom_query.sql

@@ -31,5 +31,4 @@ SELECT Count(*)
                              ON l13.l_partkey = l14.l_partkey 
                 LEFT OUTER JOIN lineitem l15 
                              ON l14.l_partkey = l15.l_partkey) 
-        ORDER  BY l0.l_partkey) AS foo; 
-
+        ORDER  BY l0.l_partkey) AS foo;

src/test/isolation2/sql_isolation_testcase.py

@@ -471,7 +471,7 @@ class SQLIsolationExecutor(object):
                     command_part = line
                 if command_part == "" or command_part == "\n":
                     print >>output_file 
-                elif command_part.endswith(";\n") or re.match(r"^\d+[q\\<]:$", line) or re.match(r"^-?\d+[SU][q\\<]:$", line):
+                elif re.match(r".*;\s*$", command_part) or re.match(r"^\d+[q\\<]:$", line) or re.match(r"^-?\d+[SU][q\\<]:$", line):
                     command += command_part
                     try:
                         self.process_command(command, output_file)
@@ -616,6 +616,27 @@ class SQLIsolationTestCase:
         -- example contents for file.sql: create function some_test_function() returning void ...
         include: path/to/some/file.sql;
         select some_helper_function();
+
+        Line continuation:
+        If a line is not ended by a semicolon ';' which is followed by 0 or more spaces, the line will be combined with next line and
+        sent together as a single statement.
+
+        e.g.: Send to the server separately:
+        1: SELECT * FROM t1; -> send "SELECT * FROM t1;"
+        SELECT * FROM t2; -> send "SELECT * FROM t2;"
+
+        e.g.: Send to the server once:
+        1: SELECT * FROM
+        t1; SELECT * FROM t2; -> "send SELECT * FROM t1; SELECT * FROM t2;"
+
+        ATTENTION:
+        Send multi SQL statements once:
+        Multi SQL statements can be sent at once, but there are some known issues. Generally only the last query result will be printed.
+        But due to the difficulties of dealing with semicolons insides quotes, we always echo the first SQL command instead of the last
+        one if query() returns None. This created some strange issues like:
+
+        CREATE TABLE t1 (a INT); INSERT INTO t1 SELECT generate_series(1,1000);
+        CREATE 1000 (Should be INSERT 1000, but here the CREATE is taken due to the limitation)
     """
 
     def run_sql_file(self, sql_file, out_file = None, out_dir = None, optimizer = None):