diff --git a/deps/oblib/src/common/object/ob_object.cpp b/deps/oblib/src/common/object/ob_object.cpp
index 41f59f6edc5deb8ba02fe2dc8d1f40d3a40093f6..3ea4e4fa9ad794d75f6881671e00cf3506c87e49 100644
--- a/deps/oblib/src/common/object/ob_object.cpp
+++ b/deps/oblib/src/common/object/ob_object.cpp
@@ -570,7 +570,30 @@ int ObObj::deep_copy(const ObObj& src, char* buf, const int64_t size, int64_t& p
   return ret;
 }
 
-bool ObObj::can_compare(const ObObj& other) const
+void* ObObj::get_deep_copy_obj_ptr()
+{
+  void * ptr = NULL;
+  if (ob_is_string_type(this->get_type())) {
+    // val_len_ == 0 is empty string, and it may point to unexpected address
+    // Therefore, reset it to NULL
+    if (val_len_ != 0) {
+      ptr = (void *)v_.string_;
+    }
+  } else if (ob_is_raw(this->get_type())) {
+    ptr = (void *)v_.string_;
+  } else if (ob_is_number_tc(this->get_type())) {
+    ptr = (void *)v_.nmb_digits_;
+  } else if (ob_is_rowid_tc(this->get_type())) {
+    ptr = (void *)v_.string_;
+  } else if (ob_is_lob_locator(this->get_type())) {
+    ptr = (void *)&v_.lob_locator_;
+  } else {
+    // do nothing
+  }
+  return ptr;
+}
+
+bool ObObj::can_compare(const ObObj &other) const
 {
   obj_cmp_func cmp_func = NULL;
   return (is_min_value() || is_max_value() || other.is_min_value() || other.is_max_value() ||
diff --git a/deps/oblib/src/common/object/ob_object.h b/deps/oblib/src/common/object/ob_object.h
index 374059d61b2f63f1059d25e519e1ecf023fa7cf3..e6505a266087b8ac85e0c643829a9b91e54ad00f 100644
--- a/deps/oblib/src/common/object/ob_object.h
+++ b/deps/oblib/src/common/object/ob_object.h
@@ -2084,10 +2084,11 @@ public:
   //@{  deep copy
   bool need_deep_copy() const;
   OB_INLINE int64_t get_deep_copy_size() const;
-  int deep_copy(const ObObj& src, char* buf, const int64_t size, int64_t& pos);
-  void set_data_ptr(void* data_ptr);
-  const void* get_data_ptr() const;
-  // return byte length
+  int deep_copy(const ObObj &src, char *buf, const int64_t size, int64_t &pos);
+  void* get_deep_copy_obj_ptr();
+  void set_data_ptr(void *data_ptr);
+  const void *get_data_ptr() const;
+  //return byte length
   int64_t get_data_length() const;
 
   template <typename Allocator>
diff --git a/deps/oblib/src/lib/ob_define.h b/deps/oblib/src/lib/ob_define.h
index 664fde7f88d13b9db5098f5d22730e0947ace3d6..9e6984c05f0693c123a02369b069737830b897c7 100644
--- a/deps/oblib/src/lib/ob_define.h
+++ b/deps/oblib/src/lib/ob_define.h
@@ -818,6 +818,9 @@ const uint64_t OB_ORA_SYS_DATABASE_ID = 6;
 const uint64_t OB_ORA_LBACSYS_DATABASE_ID = 7;
 const uint64_t OB_ORA_AUDITOR_DATABASE_ID = 8;
 const char* const OB_ORA_PUBLIC_SCHEMA_NAME = "PUBLIC";
+// not actual database, only for using and creating outlines without specified database
+const uint64_t OB_OUTLINE_DEFAULT_DATABASE_ID = 9;
+const char* const OB_OUTLINE_DEFAULT_DATABASE_NAME = "__outline_default_db";
 
 // sys unit associated const
 const uint64_t OB_SYS_UNIT_CONFIG_ID = 1;
diff --git a/src/observer/mysql/ob_mysql_request_manager.h b/src/observer/mysql/ob_mysql_request_manager.h
index a8b4a8355bff30c7ecc06d9726a1b1804838e796..29a88d7ddd7c7beeb6c8d1a0cea3f327635c3571 100644
--- a/src/observer/mysql/ob_mysql_request_manager.h
+++ b/src/observer/mysql/ob_mysql_request_manager.h
@@ -71,7 +71,7 @@ public:
   static const int32_t BATCH_RELEASE_COUNT = 50000;
   static const int32_t MAX_RELEASE_TIME = 5 * 1000;  // 5ms
   static const int64_t US_PER_HOUR = 3600000000;
-  static const int64_t MAX_QUEUE_SIZE = 1000000;           // 100w
+  static const int64_t MAX_QUEUE_SIZE = 10000000;           // 10m
   static const int64_t MINI_MODE_MAX_QUEUE_SIZE = 100000;  // 10w
   // start to eliminate when sql_audit more than 9 millions records
   static const int64_t HIGH_LEVEL_EVICT_SIZE = 9000000;  // 900w
diff --git a/src/observer/ob_inner_sql_connection.cpp b/src/observer/ob_inner_sql_connection.cpp
index 5b507f790c06bb01992553ffdb70965883fecbea..a078ebea77ed99e154a268cf5fc032ca07e2c0ac 100644
--- a/src/observer/ob_inner_sql_connection.cpp
+++ b/src/observer/ob_inner_sql_connection.cpp
@@ -473,6 +473,10 @@ int ObInnerSQLConnection::process_retry(
   if (need_retry) {
     LOG_WARN("need retry, set ret to OB_SUCCESS", K(ret), K(last_ret), K(retry_cnt));
     retry_info.set_last_query_retry_err(last_ret);
+    if (OB_ISNULL(extern_session_)) {
+    } else {
+      extern_session_->get_retry_info_for_update().set_last_query_retry_err(last_ret);
+    }
     ret = OB_SUCCESS;
   }
   return ret;
diff --git a/src/observer/virtual_table/ob_tenant_virtual_outline.cpp b/src/observer/virtual_table/ob_tenant_virtual_outline.cpp
index 89b6e34298a5084d193e9ab00fd5f390fe6a2ff0..c131a1b57b1f80a72d3754f17888192364149ed2 100644
--- a/src/observer/virtual_table/ob_tenant_virtual_outline.cpp
+++ b/src/observer/virtual_table/ob_tenant_virtual_outline.cpp
@@ -156,7 +156,10 @@ int ObTenantVirtualOutline::fill_cells(const ObOutlineInfo* outline_info)
         }
         case DATABASE_NAME: {
           DBInfo db_info;
-          if (OB_FAIL(database_infos_.get_refactored(outline_info->get_database_id(), db_info))) {
+          if (outline_info->get_database_id()==OB_OUTLINE_DEFAULT_DATABASE_ID) {
+            cells[cell_idx].set_varchar(OB_OUTLINE_DEFAULT_DATABASE_NAME);
+            cells[cell_idx].set_collation_type(ObCharset::get_default_collation(ObCharset::get_default_charset()));
+          } else if (OB_FAIL(database_infos_.get_refactored(outline_info->get_database_id(), db_info))) {
             LOG_WARN("fail to ge value from database_infos", K(ret), K(outline_info->get_database_id()));
           } else {
             cells[cell_idx].set_varchar(db_info.db_name_);
@@ -224,6 +227,10 @@ int ObTenantVirtualOutline::is_output_outline(const ObOutlineInfo* outline_info,
     LOG_WARN("parameter is NULL", K(ret), K(outline_info), K(schema_guard_));
   } else if (outline_info->get_outline_content_str().empty()) {
     is_output = false;
+  } else if (outline_info->get_database_id() == OB_OUTLINE_DEFAULT_DATABASE_ID) {
+    // __outline_default_db is a logical table and has no physical schema. 
+    // Therefore, always output this. 
+    is_output = true;
   } else if (OB_FAIL(is_database_recycle(outline_info->get_database_id(), is_recycle))) {
     LOG_WARN("fail to judge database recycle", K(ret), KPC(outline_info));
   } else {
diff --git a/src/rootserver/ob_ddl_service.cpp b/src/rootserver/ob_ddl_service.cpp
index e0bd292912d449409da3e6e380ac8d8433dab162..fcb992fca90c55d6beee5e332b7580c351169ff5 100644
--- a/src/rootserver/ob_ddl_service.cpp
+++ b/src/rootserver/ob_ddl_service.cpp
@@ -18807,13 +18807,15 @@ int ObDDLService::drop_outline(const obrpc::ObDropOutlineArg& arg)
     uint64_t database_id = OB_INVALID_ID;
     if (OB_SUCC(ret)) {
       bool database_exist = false;
-      if (OB_FAIL(schema_service_->check_database_exist(tenant_id, database_name, database_id, database_exist))) {
-        LOG_WARN("failed to check database exist!",
-            K(tenant_id),
-            K(database_name),
-            K(database_id),
-            K(database_exist),
-            K(ret));
+      if (database_name == OB_OUTLINE_DEFAULT_DATABASE_NAME) {
+        database_id = OB_OUTLINE_DEFAULT_DATABASE_ID;
+        database_exist = true;
+      } else if (OB_FAIL(schema_service_->check_database_exist(tenant_id,
+                                                        database_name,
+                                                        database_id,
+                                                        database_exist))) {
+        LOG_WARN("failed to check database exist!", K(tenant_id), K(database_name),
+                 K(database_id), K(database_exist), K(ret));
       } else if (!database_exist) {
         ret = OB_ERR_BAD_DATABASE;
         LOG_USER_ERROR(OB_ERR_BAD_DATABASE, database_name.length(), database_name.ptr());
diff --git a/src/rootserver/ob_root_service.cpp b/src/rootserver/ob_root_service.cpp
index fcb4fd50c7edd50856367d181bf344a6ee73218d..7108678d242d79128709a940b1b38f97478f0a3a 100644
--- a/src/rootserver/ob_root_service.cpp
+++ b/src/rootserver/ob_root_service.cpp
@@ -6357,6 +6357,9 @@ int ObRootService::create_outline(const ObCreateOutlineArg& arg)
     const ObDatabaseSchema* db_schema = NULL;
     if (OB_FAIL(ddl_service_.get_tenant_schema_guard_with_version_in_inner_table(tenant_id, schema_guard))) {
       LOG_WARN("get schema guard in inner table failed", K(ret));
+    } else if (database_name == OB_OUTLINE_DEFAULT_DATABASE_NAME) {
+      // if not specify database, set default database name and database id;
+      outline_info.set_database_id(OB_OUTLINE_DEFAULT_DATABASE_ID);
     } else if (OB_FAIL(schema_guard.get_database_schema(tenant_id, database_name, db_schema))) {
       LOG_WARN("get database schema failed", K(ret));
     } else if (NULL == db_schema) {
diff --git a/src/sql/engine/ob_physical_plan.h b/src/sql/engine/ob_physical_plan.h
index 3b51d461819f31be6921a311b2392aaee873716f..fa82d47ce9211c59c12c30f64c382c320ff258ef 100644
--- a/src/sql/engine/ob_physical_plan.h
+++ b/src/sql/engine/ob_physical_plan.h
@@ -90,18 +90,8 @@ public:
 
   virtual void destroy();
   virtual void reset();
-  void set_is_last_open_succ(bool val)
-  {
-    stat_.is_last_open_succ_ = val;
-  }
-  bool is_last_open_succ() const
-  {
-    return stat_.is_last_open_succ_;
-  }
-  bool from_plan_baseline() const
-  {
-    return common::OB_INVALID_ID != stat_.bl_info_.plan_baseline_id_;
-  }
+  void set_is_last_exec_succ(bool val) { stat_.is_last_exec_succ_ = val; }
+  bool is_last_exec_succ() const { return stat_.is_last_exec_succ_; }
   const ObString& get_constructed_sql() const
   {
     return stat_.bl_info_.key_.constructed_sql_;
diff --git a/src/sql/ob_result_set.cpp b/src/sql/ob_result_set.cpp
index 1786b42795ed865bac5f1d27882f941c4487a263..9b5af87d9418ce7a5a2d2fd2a8fd5129fb10c2e0 100644
--- a/src/sql/ob_result_set.cpp
+++ b/src/sql/ob_result_set.cpp
@@ -128,12 +128,6 @@ OB_INLINE int ObResultSet::open_plan()
         }
       }
     }
-
-    if (OB_FAIL(ret)) {
-      physical_plan_->set_is_last_open_succ(false);
-    } else {
-      physical_plan_->set_is_last_open_succ(true);
-    }
   }
   return ret;
 }
@@ -143,6 +137,19 @@ int ObResultSet::sync_open()
   int ret = OB_SUCCESS;
   OZ(execute());
   OZ(open());
+
+  if (OB_NOT_NULL(cmd_)) {
+    // cmd not set
+  } else if (ret == OB_NOT_INIT) {
+    // phy plan not init, do nothing
+  } else if (OB_ISNULL(physical_plan_)) {
+    LOG_WARN("empty physical plan"); 
+  } else if (OB_FAIL(ret)) {
+    physical_plan_->set_is_last_exec_succ(false);
+  } else {
+    physical_plan_->set_is_last_exec_succ(true);
+  }
+
   return ret;
 }
 
@@ -478,12 +485,15 @@ OB_INLINE int ObResultSet::end_participant(const bool is_rollback)
 int ObResultSet::get_next_row(const common::ObNewRow*& row)
 {
   int& ret = errcode_;
-  if (OB_LIKELY(NULL != physical_plan_)) {  // take this branch more frequently
+  // last_exec_succ default values is true
+  if (OB_LIKELY(NULL != physical_plan_)) { // take this branch more frequently
     if (OB_ISNULL(exec_result_)) {
       ret = OB_ERR_UNEXPECTED;
       LOG_WARN("exec result is null", K(ret));
     } else if (OB_FAIL(exec_result_->get_next_row(get_exec_context(), row))) {
       if (OB_ITER_END != ret) {
+        // marked last execute status
+        physical_plan_->set_is_last_exec_succ(false);
         LOG_WARN("get next row from exec result failed", K(ret));
       }
     } else {
diff --git a/src/sql/ob_sql.cpp b/src/sql/ob_sql.cpp
index 8479a302c344668dd4bfa30ec2cf596ca6849f2e..b831c1988dfc279f23670cca39e5c8917555b9e9 100644
--- a/src/sql/ob_sql.cpp
+++ b/src/sql/ob_sql.cpp
@@ -1154,13 +1154,20 @@ inline int ObSql::handle_text_query(const ObString& stmt, ObSqlCtx& context, ObR
   } else {
     context.cur_sql_ = trimed_stmt;
     pc_ctx = new (pc_ctx) ObPlanCacheCtx(trimed_stmt,
-        false, /*is_ps_mode*/
-        allocator,
-        context,
-        ectx,
-        tenant_id);
-    if (OB_FAIL(session.get_database_id(pc_ctx->bl_key_.db_id_))) {
+                                         false, /*is_ps_mode*/
+                                         allocator,
+                                         context,
+                                         ectx,
+                                         tenant_id);
+    uint64_t database_id = OB_INVALID_ID;
+
+    if (OB_FAIL(session.get_database_id(database_id))) {
       LOG_WARN("Failed to get database id", K(ret));
+    } else if (FALSE_IT(pc_ctx->bl_key_.db_id_ =
+                                  (database_id == OB_INVALID_ID) ?
+                                      OB_OUTLINE_DEFAULT_DATABASE_ID:
+                                      database_id)) {
+      // do nothing
     } else if (!use_plan_cache) {
       if (context.multi_stmt_item_.is_batched_multi_stmt()) {
         ret = OB_BATCHED_MULTI_STMT_ROLLBACK;
diff --git a/src/sql/plan_cache/ob_plan_cache.cpp b/src/sql/plan_cache/ob_plan_cache.cpp
index f52de4a8abeacda3bf0505437c472430b69cada5..9141653825336603f531fc9e966ac6afad0c0eee 100644
--- a/src/sql/plan_cache/ob_plan_cache.cpp
+++ b/src/sql/plan_cache/ob_plan_cache.cpp
@@ -1606,8 +1606,13 @@ int ObPlanCache::construct_plan_cache_key(ObPlanCacheCtx& plan_ctx, ObjNameSpace
 int ObPlanCache::construct_plan_cache_key(ObSQLSessionInfo& session, ObjNameSpace ns, ObPlanCacheKey& pc_key)
 {
   int ret = OB_SUCCESS;
-  if (OB_FAIL(session.get_database_id(pc_key.db_id_))) {
+  uint64_t database_id = OB_INVALID_ID;
+  if (OB_FAIL(session.get_database_id(database_id))) {
     LOG_WARN("get database id failed", K(ret));
+  } else if (FALSE_IT(pc_key.db_id_ = (database_id == OB_INVALID_ID) ? 
+                                            OB_OUTLINE_DEFAULT_DATABASE_ID 
+                                            : database_id)) {
+    // do nothing
   } else {
     pc_key.namespace_ = ns;
     pc_key.sys_vars_str_ = session.get_sys_var_in_pc_str();
diff --git a/src/sql/plan_cache/ob_plan_cache.h b/src/sql/plan_cache/ob_plan_cache.h
index 733bdf9692b9e2b64875625340d2958274438d95..4e88c427463b3a2543c2ea8bc1f22f05f7b15c4f 100644
--- a/src/sql/plan_cache/ob_plan_cache.h
+++ b/src/sql/plan_cache/ob_plan_cache.h
@@ -294,11 +294,11 @@ public:
   int dump_all_objs() const;
   template <DumpType dump_type>
   int dump_deleted_objs(common::ObIArray<DeletedCacheObjInfo>& deleted_objs, const int64_t safe_timestamp) const;
-  static common::ObMemAttr get_mem_attr()
+  common::ObMemAttr get_mem_attr()
   {
     common::ObMemAttr attr;
     attr.label_ = ObNewModIds::OB_SQL_PLAN_CACHE;
-    attr.tenant_id_ = OB_INVALID_ID;
+    attr.tenant_id_ = tenant_id_;
     attr.ctx_id_ = ObCtxIds::PLAN_CACHE_CTX_ID;
     return attr;
   }
diff --git a/src/sql/plan_cache/ob_plan_cache_util.h b/src/sql/plan_cache/ob_plan_cache_util.h
index d73461827b04bdb7249934eb78eceee3f3f9b4f3..510b2d13943fdfde00257266a5cfc1f8723e4637 100644
--- a/src/sql/plan_cache/ob_plan_cache_util.h
+++ b/src/sql/plan_cache/ob_plan_cache_util.h
@@ -698,7 +698,7 @@ struct ObPlanStat {
   int64_t expected_worker_count_;
   int64_t outline_version_;
   int64_t outline_id_;
-  bool is_last_open_succ_;
+  bool is_last_exec_succ_;
   common::ObString sp_info_str_;
   common::ObString param_infos_;
   common::ObString sys_vars_str_;
@@ -782,7 +782,7 @@ struct ObPlanStat {
         expected_worker_count_(-1),
         outline_version_(common::OB_INVALID_VERSION),
         outline_id_(common::OB_INVALID_ID),
-        is_last_open_succ_(true),
+        is_last_exec_succ_(true),
         is_evolution_(false),
         asyn_baseline_stat_(ASYN_NOTHING),
         is_bind_sensitive_(false),
@@ -847,7 +847,7 @@ struct ObPlanStat {
         expected_worker_count_(rhs.expected_worker_count_),
         outline_version_(rhs.outline_version_),
         outline_id_(rhs.outline_id_),
-        is_last_open_succ_(rhs.is_last_open_succ_),
+        is_last_exec_succ_(rhs.is_last_exec_succ_),
         is_evolution_(rhs.is_evolution_),
         asyn_baseline_stat_(rhs.asyn_baseline_stat_),
         bl_info_(rhs.bl_info_),
@@ -996,7 +996,7 @@ struct ObPlanStat {
       K_(execute_times), K_(disk_reads), K_(direct_writes), K_(buffer_gets), K_(application_wait_time),
       K_(concurrency_wait_time), K_(user_io_wait_time), K_(rows_processed), K_(elapsed_time), K_(cpu_time),
       K_(large_querys), K_(delayed_large_querys), K_(outline_version), K_(outline_id), K_(is_evolution),
-      K_(is_last_open_succ), K_(is_bind_sensitive), K_(is_bind_aware), K_(is_last_open_succ), K_(timeout_count),
+      K_(is_last_exec_succ), K_(is_bind_sensitive), K_(is_bind_aware), K_(is_last_exec_succ), K_(timeout_count),
       K_(bl_info));
 };
 
diff --git a/src/sql/plan_cache/ob_plan_cache_value.cpp b/src/sql/plan_cache/ob_plan_cache_value.cpp
index c340e7c9598e614742fca20c361dd8103f79908f..3635d4729eaef4bbd9d5a8487bb1d41d584f3ecc 100644
--- a/src/sql/plan_cache/ob_plan_cache_value.cpp
+++ b/src/sql/plan_cache/ob_plan_cache_value.cpp
@@ -151,10 +151,12 @@ ObPlanCacheValue::ObPlanCacheValue()
 int ObPlanCacheValue::init(ObPCVSet* pcv_set, const ObCacheObject* cache_obj, ObPlanCacheCtx& pc_ctx)
 {
   int ret = OB_SUCCESS;
-  ObMemAttr mem_attr = ObPlanCache::get_mem_attr();
-  if (OB_ISNULL(pcv_set) || OB_ISNULL(cache_obj)) {
+  ObMemAttr mem_attr;
+  if (OB_ISNULL(pcv_set) || OB_ISNULL(cache_obj) || OB_ISNULL(pcv_set->get_plan_cache())) {
     ret = OB_INVALID_ARGUMENT;
     LOG_WARN("invalid argument", K(pcv_set), K(cache_obj));
+  } else if (FALSE_IT(mem_attr = pcv_set->get_plan_cache()->get_mem_attr())) {
+      // do nothing
   } else if (OB_ISNULL(pc_alloc_ = pcv_set->get_pc_allocator())) {
     LOG_WARN("invalid argument", K(pcv_set->get_pc_allocator()));
   } else if (OB_FAIL(outline_params_wrapper_.set_allocator(pc_alloc_, mem_attr))) {
@@ -840,6 +842,20 @@ void ObPlanCacheValue::reset()
         not_param_info_.at(i).raw_text_.reset();
       }
     }
+
+    for (int64_t i = 0; i < not_param_var_.count(); i++) {
+      // deep-copy destory
+      // free v
+      ObObjParam param = not_param_var_.at(i).ps_param_;
+      void * ptr = param.get_deep_copy_obj_ptr();
+      if (NULL == ptr){
+        // do nothing
+      } else {
+        pc_alloc_->free(ptr);
+        not_param_var_.at(i).ps_param_.reset();
+      }
+    }
+
     if (NULL != outline_signature_.ptr()) {
       pc_alloc_->free(outline_signature_.ptr());
       outline_signature_.reset();
@@ -851,6 +867,7 @@ void ObPlanCacheValue::reset()
   }
   not_param_info_.reset();
   not_param_index_.reset();
+  not_param_var_.reset();
   neg_param_index_.reset();
   param_charset_type_.reset();
   sql_traits_.reset();
diff --git a/src/sql/plan_cache/ob_plan_set.cpp b/src/sql/plan_cache/ob_plan_set.cpp
index b99d46bcc72f1d19358f36fbbcc7c09b33d21f0d..61d26473aee709af15209019034049db4e65cf4a 100644
--- a/src/sql/plan_cache/ob_plan_set.cpp
+++ b/src/sql/plan_cache/ob_plan_set.cpp
@@ -1195,8 +1195,9 @@ int ObSqlPlanSet::get_local_plan_direct(ObPlanCacheCtx& pc_ctx, bool& is_direct_
       plan = local_plan_;
     }
     if (OB_SUCC(ret) && plan != NULL) {
-      int last_retry_err = pc_ctx.sql_ctx_.session_info_->get_retry_info().get_last_query_retry_err();
-      if (plan->is_last_open_succ()) {
+      int last_retry_err = pc_ctx.sql_ctx_.session_info_
+                             ->get_retry_info().get_last_query_retry_err();
+      if (plan->is_last_exec_succ()) {
         is_direct_local_plan = true;
       } else if (pc_ctx.sql_ctx_.session_info_->get_is_in_retry() && is_local_plan_opt_allowed(last_retry_err)) {
         is_direct_local_plan = true;
diff --git a/src/sql/resolver/ddl/ob_outline_resolver.cpp b/src/sql/resolver/ddl/ob_outline_resolver.cpp
index 421003de6fe9cfa421e2f3ed9b6a902066a8cd23..1f972f6c46175e20d0c3bf63ed80ea4f63a5a5a9 100644
--- a/src/sql/resolver/ddl/ob_outline_resolver.cpp
+++ b/src/sql/resolver/ddl/ob_outline_resolver.cpp
@@ -60,8 +60,7 @@ int ObOutlineResolver::resolve_outline_name(const ParseNode* node, ObString& db_
     bool perserve_lettercase = share::is_oracle_mode() ? true : (mode != OB_LOWERCASE_AND_INSENSITIVE);
     if (NULL == db_name_node) {
       if (session_info_->get_database_name().empty()) {
-        ret = OB_ERR_NO_DB_SELECTED;
-        LOG_WARN("no database selected");
+        db_name = OB_OUTLINE_DEFAULT_DATABASE_NAME;
       } else {
         db_name = session_info_->get_database_name();
       }