Revert "Don't lock partitions pruned by initial pruning"

As pointed out by Tom Lane, the patch introduced fragile and invasive
design around plan invalidation handling when locking of prunable
partitions was deferred from plancache.c to the executor. In
particular, it violated assumptions about CachedPlan immutability and
altered executor APIs in ways that are difficult to justify given the
added complexity and overhead.

This also removes the firstResultRels field added to PlannedStmt in
commit 28317de72, which was intended to support deferred locking of
certain ModifyTable result relations.

Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/605328.1747710381@sss.pgh.pa.us

8 files changed, 14 insertions, 52 deletions

diff --git a/src/backend/commands/copyto.c b/src/backend/commands/copyto.c
index f87e405351d..ea6f18f2c80 100644
--- a/src/backend/commands/copyto.c
+++ b/src/backend/commands/copyto.c
@@ -835,7 +835,7 @@ BeginCopyTo(ParseState *pstate,
 		((DR_copy *) dest)->cstate = cstate;
 
 		/* Create a QueryDesc requesting no output */
-		cstate->queryDesc = CreateQueryDesc(plan, NULL, pstate->p_sourcetext,
+		cstate->queryDesc = CreateQueryDesc(plan, pstate->p_sourcetext,
 											GetActiveSnapshot(),
 											InvalidSnapshot,
 											dest, NULL, NULL, 0);
@@ -845,8 +845,7 @@ BeginCopyTo(ParseState *pstate,
 		 *
 		 * ExecutorStart computes a result tupdesc for us
 		 */
-		if (!ExecutorStart(cstate->queryDesc, 0))
-			elog(ERROR, "ExecutorStart() failed unexpectedly");
+		ExecutorStart(cstate->queryDesc, 0);
 
 		tupDesc = cstate->queryDesc->tupDesc;
 	}
diff --git a/src/backend/commands/createas.c b/src/backend/commands/createas.c
index 0a4155773eb..dfd2ab8e862 100644
--- a/src/backend/commands/createas.c
+++ b/src/backend/commands/createas.c
@@ -334,13 +334,12 @@ ExecCreateTableAs(ParseState *pstate, CreateTableAsStmt *stmt,
 		UpdateActiveSnapshotCommandId();
 
 		/* Create a QueryDesc, redirecting output to our tuple receiver */
-		queryDesc = CreateQueryDesc(plan, NULL, pstate->p_sourcetext,
+		queryDesc = CreateQueryDesc(plan, pstate->p_sourcetext,
 									GetActiveSnapshot(), InvalidSnapshot,
 									dest, params, queryEnv, 0);
 
 		/* call ExecutorStart to prepare the plan for execution */
-		if (!ExecutorStart(queryDesc, GetIntoRelEFlags(into)))
-			elog(ERROR, "ExecutorStart() failed unexpectedly");
+		ExecutorStart(queryDesc, GetIntoRelEFlags(into));
 
 		/* run the plan to completion */
 		ExecutorRun(queryDesc, ForwardScanDirection, 0);
diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index 786ee865f14..09ea30dfb92 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -369,8 +369,7 @@ standard_ExplainOneQuery(Query *query, int cursorOptions,
 	}
 
 	/* run it (if needed) and produce output */
-	ExplainOnePlan(plan, NULL, NULL, -1, into, es, queryString, params,
-				   queryEnv,
+	ExplainOnePlan(plan, into, es, queryString, params, queryEnv,
 				   &planduration, (es->buffers ? &bufusage : NULL),
 				   es->memory ? &mem_counters : NULL);
 }
@@ -492,9 +491,7 @@ ExplainOneUtility(Node *utilityStmt, IntoClause *into, ExplainState *es,
  * to call it.
  */
 void
-ExplainOnePlan(PlannedStmt *plannedstmt, CachedPlan *cplan,
-			   CachedPlanSource *plansource, int query_index,
-			   IntoClause *into, ExplainState *es,
+ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, ExplainState *es,
 			   const char *queryString, ParamListInfo params,
 			   QueryEnvironment *queryEnv, const instr_time *planduration,
 			   const BufferUsage *bufusage,
@@ -550,7 +547,7 @@ ExplainOnePlan(PlannedStmt *plannedstmt, CachedPlan *cplan,
 		dest = None_Receiver;
 
 	/* Create a QueryDesc for the query */
-	queryDesc = CreateQueryDesc(plannedstmt, cplan, queryString,
+	queryDesc = CreateQueryDesc(plannedstmt, queryString,
 								GetActiveSnapshot(), InvalidSnapshot,
 								dest, params, queryEnv, instrument_option);
 
@@ -564,17 +561,8 @@ ExplainOnePlan(PlannedStmt *plannedstmt, CachedPlan *cplan,
 	if (into)
 		eflags |= GetIntoRelEFlags(into);
 
-	/* Prepare the plan for execution. */
-	if (queryDesc->cplan)
-	{
-		ExecutorStartCachedPlan(queryDesc, eflags, plansource, query_index);
-		Assert(queryDesc->planstate);
-	}
-	else
-	{
-		if (!ExecutorStart(queryDesc, eflags))
-			elog(ERROR, "ExecutorStart() failed unexpectedly");
-	}
+	/* call ExecutorStart to prepare the plan for execution */
+	ExecutorStart(queryDesc, eflags);
 
 	/* Execute the plan for statistics if asked for */
 	if (es->analyze)
diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c
index 73c52e970f6..e6f9ab6dfd6 100644
--- a/src/backend/commands/extension.c
+++ b/src/backend/commands/extension.c
@@ -993,13 +993,11 @@ execute_sql_string(const char *sql, const char *filename)
 				QueryDesc  *qdesc;
 
 				qdesc = CreateQueryDesc(stmt,
-										NULL,
 										sql,
 										GetActiveSnapshot(), NULL,
 										dest, NULL, NULL, 0);
 
-				if (!ExecutorStart(qdesc, 0))
-					elog(ERROR, "ExecutorStart() failed unexpectedly");
+				ExecutorStart(qdesc, 0);
 				ExecutorRun(qdesc, ForwardScanDirection, 0);
 				ExecutorFinish(qdesc);
 				ExecutorEnd(qdesc);
diff --git a/src/backend/commands/matview.c b/src/backend/commands/matview.c
index e7854add178..27c2cb26ef5 100644
--- a/src/backend/commands/matview.c
+++ b/src/backend/commands/matview.c
@@ -438,13 +438,12 @@ refresh_matview_datafill(DestReceiver *dest, Query *query,
 	UpdateActiveSnapshotCommandId();
 
 	/* Create a QueryDesc, redirecting output to our tuple receiver */
-	queryDesc = CreateQueryDesc(plan, NULL, queryString,
+	queryDesc = CreateQueryDesc(plan, queryString,
 								GetActiveSnapshot(), InvalidSnapshot,
 								dest, NULL, NULL, 0);
 
 	/* call ExecutorStart to prepare the plan for execution */
-	if (!ExecutorStart(queryDesc, 0))
-		elog(ERROR, "ExecutorStart() failed unexpectedly");
+	ExecutorStart(queryDesc, 0);
 
 	/* run the plan */
 	ExecutorRun(queryDesc, ForwardScanDirection, 0);
diff --git a/src/backend/commands/portalcmds.c b/src/backend/commands/portalcmds.c
index 4c2ac045224..e7c8171c102 100644
--- a/src/backend/commands/portalcmds.c
+++ b/src/backend/commands/portalcmds.c
@@ -117,7 +117,6 @@ PerformCursorOpen(ParseState *pstate, DeclareCursorStmt *cstmt, ParamListInfo pa
 					  queryString,
 					  CMDTAG_SELECT,	/* cursor's query is always a SELECT */
 					  list_make1(plan),
-					  NULL,
 					  NULL);
 
 	/*----------
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index bf7d2b2309f..34b6410d6a2 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -205,8 +205,7 @@ ExecuteQuery(ParseState *pstate,
 					  query_string,
 					  entry->plansource->commandTag,
 					  plan_list,
-					  cplan,
-					  entry->plansource);
+					  cplan);
 
 	/*
 	 * For CREATE TABLE ... AS EXECUTE, we must verify that the prepared
@@ -586,7 +585,6 @@ ExplainExecuteQuery(ExecuteStmt *execstmt, IntoClause *into, ExplainState *es,
 	MemoryContextCounters mem_counters;
 	MemoryContext planner_ctx = NULL;
 	MemoryContext saved_ctx = NULL;
-	int			query_index = 0;
 
 	if (es->memory)
 	{
@@ -659,8 +657,7 @@ ExplainExecuteQuery(ExecuteStmt *execstmt, IntoClause *into, ExplainState *es,
 		PlannedStmt *pstmt = lfirst_node(PlannedStmt, p);
 
 		if (pstmt->commandType != CMD_UTILITY)
-			ExplainOnePlan(pstmt, cplan, entry->plansource, query_index,
-						   into, es, query_string, paramLI, pstate->p_queryEnv,
+			ExplainOnePlan(pstmt, into, es, query_string, paramLI, pstate->p_queryEnv,
 						   &planduration, (es->buffers ? &bufusage : NULL),
 						   es->memory ? &mem_counters : NULL);
 		else
@@ -671,8 +668,6 @@ ExplainExecuteQuery(ExecuteStmt *execstmt, IntoClause *into, ExplainState *es,
 		/* Separate plans with an appropriate separator */
 		if (lnext(plan_list, p) != NULL)
 			ExplainSeparatePlans(es);
-
-		query_index++;
 	}
 
 	if (estate)
diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c
index c9f61130c69..67f8e70f9c1 100644
--- a/src/backend/commands/trigger.c
+++ b/src/backend/commands/trigger.c
@@ -5058,21 +5058,6 @@ AfterTriggerBeginQuery(void)
 
 
 /* ----------
- * AfterTriggerAbortQuery()
- *
- * Called by standard_ExecutorEnd() if the query execution was aborted due to
- * the plan becoming invalid during initialization.
- * ----------
- */
-void
-AfterTriggerAbortQuery(void)
-{
-	/* Revert the actions of AfterTriggerBeginQuery(). */
-	afterTriggers.query_depth--;
-}
-
-
-/* ----------
  * AfterTriggerEndQuery()
  *
  *	Called after one query has been completely processed. At this time