Set query ID for inner queries of CREATE TABLE AS and DECLARE

Some utility statements contain queries that can be planned and
executed: CREATE TABLE AS and DECLARE CURSOR.  This commit adds query ID
computation for the inner queries executed by these two utility
commands, with and without EXPLAIN.  This change leads to four new
callers of JumbleQuery() and post_parse_analyze_hook() so as extensions
can decide what to do with this new data.

Previously, extensions relying on the query ID, like pg_stat_statements,
were not able to track these nested queries as the query_id was 0.

For pg_stat_statements, this commit leads to additions under !toplevel
when pg_stat_statements.track is set to "all", as shown in its
regression tests.  The output of EXPLAIN for these two utilities gains a
"Query Identifier" if compute_query_id is enabled.

Author: Anthonin Bonnefoy
Reviewed-by: Michael Paquier, Jian He
Discussion: https://postgr.es/m/CAO6_XqqM6S9bQ2qd=75W+yKATwoazxSNhv5sjW06fjGAtHbTUA@mail.gmail.com

src/backend/commands/createas.c

@@ -37,6 +37,8 @@
 #include "commands/view.h"
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
+#include "nodes/queryjumble.h"
+#include "parser/analyze.h"
 #include "rewrite/rewriteHandler.h"
 #include "tcop/tcopprot.h"
 #include "utils/builtins.h"
@@ -222,6 +224,7 @@ ExecCreateTableAs(ParseState *pstate, CreateTableAsStmt *stmt,
 {
 	Query	   *query = castNode(Query, stmt->query);
 	IntoClause *into = stmt->into;
+	JumbleState *jstate = NULL;
 	bool		is_matview = (into->viewQuery != NULL);
 	bool		do_refresh = false;
 	DestReceiver *dest;
@@ -236,6 +239,13 @@ ExecCreateTableAs(ParseState *pstate, CreateTableAsStmt *stmt,
 	 */
 	dest = CreateIntoRelDestReceiver(into);
 
+	/* Query contained by CTAS needs to be jumbled if requested */
+	if (IsQueryIdEnabled())
+		jstate = JumbleQuery(query);
+
+	if (post_parse_analyze_hook)
+		(*post_parse_analyze_hook) (pstate, query, jstate);
+
 	/*
 	 * The contained Query could be a SELECT, or an EXECUTE utility command.
 	 * If the latter, we just pass it off to ExecuteQuery.

src/backend/commands/explain.c

@@ -71,8 +71,7 @@ typedef struct SerializeMetrics
 
 static void ExplainOneQuery(Query *query, int cursorOptions,
 							IntoClause *into, ExplainState *es,
-							const char *queryString, ParamListInfo params,
-							QueryEnvironment *queryEnv);
+							ParseState *pstate, ParamListInfo params);
 static void ExplainPrintJIT(ExplainState *es, int jit_flags,
 							JitInstrumentation *ji);
 static void ExplainPrintSerialize(ExplainState *es,
@@ -350,7 +349,7 @@ ExplainQuery(ParseState *pstate, ExplainStmt *stmt,
 		{
 			ExplainOneQuery(lfirst_node(Query, l),
 							CURSOR_OPT_PARALLEL_OK, NULL, es,
-							pstate->p_sourcetext, params, pstate->p_queryEnv);
+							pstate, params);
 
 			/* Separate plans with an appropriate separator */
 			if (lnext(rewritten, l) != NULL)
@@ -436,24 +435,22 @@ ExplainResultDesc(ExplainStmt *stmt)
 static void
 ExplainOneQuery(Query *query, int cursorOptions,
 				IntoClause *into, ExplainState *es,
-				const char *queryString, ParamListInfo params,
-				QueryEnvironment *queryEnv)
+				ParseState *pstate, ParamListInfo params)
 {
 	/* planner will not cope with utility statements */
 	if (query->commandType == CMD_UTILITY)
 	{
-		ExplainOneUtility(query->utilityStmt, into, es, queryString, params,
-						  queryEnv);
+		ExplainOneUtility(query->utilityStmt, into, es, pstate, params);
 		return;
 	}
 
 	/* if an advisor plugin is present, let it manage things */
 	if (ExplainOneQuery_hook)
 		(*ExplainOneQuery_hook) (query, cursorOptions, into, es,
-								 queryString, params, queryEnv);
+								 pstate->p_sourcetext, params, pstate->p_queryEnv);
 	else
 		standard_ExplainOneQuery(query, cursorOptions, into, es,
-								 queryString, params, queryEnv);
+								 pstate->p_sourcetext, params, pstate->p_queryEnv);
 }
 
 /*
@@ -534,8 +531,7 @@ standard_ExplainOneQuery(Query *query, int cursorOptions,
  */
 void
 ExplainOneUtility(Node *utilityStmt, IntoClause *into, ExplainState *es,
-				  const char *queryString, ParamListInfo params,
-				  QueryEnvironment *queryEnv)
+				  ParseState *pstate, ParamListInfo params)
 {
 	if (utilityStmt == NULL)
 		return;
@@ -547,7 +543,9 @@ ExplainOneUtility(Node *utilityStmt, IntoClause *into, ExplainState *es,
 		 * ExplainOneQuery.  Copy to be safe in the EXPLAIN EXECUTE case.
 		 */
 		CreateTableAsStmt *ctas = (CreateTableAsStmt *) utilityStmt;
+		Query	   *ctas_query;
 		List	   *rewritten;
+		JumbleState *jstate = NULL;
 
 		/*
 		 * Check if the relation exists or not.  This is done at this stage to
@@ -565,11 +563,16 @@ ExplainOneUtility(Node *utilityStmt, IntoClause *into, ExplainState *es,
 			return;
 		}
 
-		rewritten = QueryRewrite(castNode(Query, copyObject(ctas->query)));
+		ctas_query = castNode(Query, copyObject(ctas->query));
+		if (IsQueryIdEnabled())
+			jstate = JumbleQuery(ctas_query);
+		if (post_parse_analyze_hook)
+			(*post_parse_analyze_hook) (pstate, ctas_query, jstate);
+		rewritten = QueryRewrite(ctas_query);
 		Assert(list_length(rewritten) == 1);
 		ExplainOneQuery(linitial_node(Query, rewritten),
 						CURSOR_OPT_PARALLEL_OK, ctas->into, es,
-						queryString, params, queryEnv);
+						pstate, params);
 	}
 	else if (IsA(utilityStmt, DeclareCursorStmt))
 	{
@@ -582,17 +585,25 @@ ExplainOneUtility(Node *utilityStmt, IntoClause *into, ExplainState *es,
 		 * be created, however.
 		 */
 		DeclareCursorStmt *dcs = (DeclareCursorStmt *) utilityStmt;
+		Query	   *dcs_query;
 		List	   *rewritten;
+		JumbleState *jstate = NULL;
 
-		rewritten = QueryRewrite(castNode(Query, copyObject(dcs->query)));
+		dcs_query = castNode(Query, copyObject(dcs->query));
+		if (IsQueryIdEnabled())
+			jstate = JumbleQuery(dcs_query);
+		if (post_parse_analyze_hook)
+			(*post_parse_analyze_hook) (pstate, dcs_query, jstate);
+
+		rewritten = QueryRewrite(dcs_query);
 		Assert(list_length(rewritten) == 1);
 		ExplainOneQuery(linitial_node(Query, rewritten),
 						dcs->options, NULL, es,
-						queryString, params, queryEnv);
+						pstate, params);
 	}
 	else if (IsA(utilityStmt, ExecuteStmt))
 		ExplainExecuteQuery((ExecuteStmt *) utilityStmt, into, es,
-							queryString, params, queryEnv);
+							pstate, params);
 	else if (IsA(utilityStmt, NotifyStmt))
 	{
 		if (es->format == EXPLAIN_FORMAT_TEXT)

src/backend/commands/portalcmds.c

@@ -28,6 +28,8 @@
 #include "executor/executor.h"
 #include "executor/tstoreReceiver.h"
 #include "miscadmin.h"
+#include "nodes/queryjumble.h"
+#include "parser/analyze.h"
 #include "rewrite/rewriteHandler.h"
 #include "tcop/pquery.h"
 #include "tcop/tcopprot.h"
@@ -44,6 +46,7 @@ PerformCursorOpen(ParseState *pstate, DeclareCursorStmt *cstmt, ParamListInfo pa
 				  bool isTopLevel)
 {
 	Query	   *query = castNode(Query, cstmt->query);
+	JumbleState *jstate = NULL;
 	List	   *rewritten;
 	PlannedStmt *plan;
 	Portal		portal;
@@ -71,6 +74,13 @@ PerformCursorOpen(ParseState *pstate, DeclareCursorStmt *cstmt, ParamListInfo pa
 				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
 				 errmsg("cannot create a cursor WITH HOLD within security-restricted operation")));
 
+	/* Query contained by DeclareCursor needs to be jumbled if requested */
+	if (IsQueryIdEnabled())
+		jstate = JumbleQuery(query);
+
+	if (post_parse_analyze_hook)
+		(*post_parse_analyze_hook) (pstate, query, jstate);
+
 	/*
 	 * Parse analysis was done already, but we still have to run the rule
 	 * rewriter.  We do not do AcquireRewriteLocks: we assume the query either

src/backend/commands/prepare.c

@@ -561,13 +561,12 @@ DropAllPreparedStatements(void)
  * "into" is NULL unless we are doing EXPLAIN CREATE TABLE AS EXECUTE,
  * in which case executing the query should result in creating that table.
  *
- * Note: the passed-in queryString is that of the EXPLAIN EXECUTE,
+ * Note: the passed-in pstate's queryString is that of the EXPLAIN EXECUTE,
  * not the original PREPARE; we get the latter string from the plancache.
  */
 void
 ExplainExecuteQuery(ExecuteStmt *execstmt, IntoClause *into, ExplainState *es,
-					const char *queryString, ParamListInfo params,
-					QueryEnvironment *queryEnv)
+					ParseState *pstate, ParamListInfo params)
 {
 	PreparedStatement *entry;
 	const char *query_string;
@@ -610,10 +609,10 @@ ExplainExecuteQuery(ExecuteStmt *execstmt, IntoClause *into, ExplainState *es,
 	/* Evaluate parameters, if any */
 	if (entry->plansource->num_params)
 	{
-		ParseState *pstate;
+		ParseState *pstate_params;
 
-		pstate = make_parsestate(NULL);
-		pstate->p_sourcetext = queryString;
+		pstate_params = make_parsestate(NULL);
+		pstate_params->p_sourcetext = pstate->p_sourcetext;
 
 		/*
 		 * Need an EState to evaluate parameters; must not delete it till end
@@ -624,12 +623,12 @@ ExplainExecuteQuery(ExecuteStmt *execstmt, IntoClause *into, ExplainState *es,
 		estate = CreateExecutorState();
 		estate->es_param_list_info = params;
 
-		paramLI = EvaluateParams(pstate, entry, execstmt->params, estate);
+		paramLI = EvaluateParams(pstate_params, entry, execstmt->params, estate);
 	}
 
 	/* Replan if needed, and acquire a transient refcount */
 	cplan = GetCachedPlan(entry->plansource, paramLI,
-						  CurrentResourceOwner, queryEnv);
+						  CurrentResourceOwner, pstate->p_queryEnv);
 
 	INSTR_TIME_SET_CURRENT(planduration);
 	INSTR_TIME_SUBTRACT(planduration, planstart);
@@ -655,12 +654,11 @@ ExplainExecuteQuery(ExecuteStmt *execstmt, IntoClause *into, ExplainState *es,
 		PlannedStmt *pstmt = lfirst_node(PlannedStmt, p);
 
 		if (pstmt->commandType != CMD_UTILITY)
-			ExplainOnePlan(pstmt, into, es, query_string, paramLI, queryEnv,
+			ExplainOnePlan(pstmt, into, es, query_string, paramLI, pstate->p_queryEnv,
 						   &planduration, (es->buffers ? &bufusage : NULL),
 						   es->memory ? &mem_counters : NULL);
 		else
-			ExplainOneUtility(pstmt->utilityStmt, into, es, query_string,
-							  paramLI, queryEnv);
+			ExplainOneUtility(pstmt->utilityStmt, into, es, pstate, paramLI);
 
 		/* No need for CommandCounterIncrement, as ExplainOnePlan did it */