From 11e0262e31e35539f50e96531559db6cd7e32160 Mon Sep 17 00:00:00 2001
From: Amit Langote <amitlan@postgresql.org>
Date: Tue, 11 Nov 2025 21:47:46 +0900
Subject: [PATCH v2 2/5] Introduce ExecutorPrep and refactor executor startup

Factor permission checks, range table initialization, and initial
partition pruning out of InitPlan() into a new ExecutorPrep()
helper.  ExecutorPrep builds an EState containing the executor
metadata needed before plan execution, including partition
pruning state where partPruneInfos are present.

ExecutorStart() now expects QueryDesc->prep to point at such an
ExecPrep object.  If no prep was supplied by the caller, it
invokes ExecutorPrep() itself and adopts the resulting EState
for the duration of the query.  This keeps the executor startup
behaviour unchanged while making the setup work callable
separately when needed.

CreateQueryDesc() grows a prep argument and stores it in the
QueryDesc.  Portals, SPI, SQL functions, and EXPLAIN are wired
to carry an optional ExecPrep pointer alongside the PlannedStmt
list, but most callers still pass NULL and let ExecutorStart()
perform the setup lazily.

Add the ExecPrep struct and ExecPrepCleanup() to encapsulate
ownership of the prepared EState and any caller specific
cleanup hook.  Update executor/README and related comments to
document the new control flow and the separation between
preparation and execution.
---
 src/backend/commands/copyto.c        |   2 +-
 src/backend/commands/createas.c      |   2 +-
 src/backend/commands/explain.c       |   7 +-
 src/backend/commands/extension.c     |   1 +
 src/backend/commands/matview.c       |   2 +-
 src/backend/commands/portalcmds.c    |   1 +
 src/backend/commands/prepare.c       |  11 +-
 src/backend/executor/README          |   8 +-
 src/backend/executor/execMain.c      | 179 +++++++++++++++++++++++----
 src/backend/executor/execParallel.c  |   1 +
 src/backend/executor/execPartition.c |   3 +
 src/backend/executor/functions.c     |   1 +
 src/backend/executor/spi.c           |  10 ++
 src/backend/tcop/postgres.c          |   2 +
 src/backend/tcop/pquery.c            |  27 +++-
 src/backend/utils/mmgr/portalmem.c   |   2 +
 src/include/commands/explain.h       |   3 +-
 src/include/executor/execdesc.h      |   3 +-
 src/include/executor/executor.h      |  11 ++
 src/include/nodes/execnodes.h        |  48 +++++++
 src/include/utils/portal.h           |   2 +
 21 files changed, 286 insertions(+), 40 deletions(-)

diff --git a/src/backend/commands/copyto.c b/src/backend/commands/copyto.c
index cef452584e5..5efbb0949c2 100644
--- a/src/backend/commands/copyto.c
+++ b/src/backend/commands/copyto.c
@@ -870,7 +870,7 @@ BeginCopyTo(ParseState *pstate,
 		((DR_copy *) dest)->cstate = cstate;
 
 		/* Create a QueryDesc requesting no output */
-		cstate->queryDesc = CreateQueryDesc(plan, pstate->p_sourcetext,
+		cstate->queryDesc = CreateQueryDesc(plan, NULL, pstate->p_sourcetext,
 											GetActiveSnapshot(),
 											InvalidSnapshot,
 											dest, NULL, NULL, 0);
diff --git a/src/backend/commands/createas.c b/src/backend/commands/createas.c
index 1ccc2e55c64..9eabe4920cd 100644
--- a/src/backend/commands/createas.c
+++ b/src/backend/commands/createas.c
@@ -334,7 +334,7 @@ ExecCreateTableAs(ParseState *pstate, CreateTableAsStmt *stmt,
 		UpdateActiveSnapshotCommandId();
 
 		/* Create a QueryDesc, redirecting output to our tuple receiver */
-		queryDesc = CreateQueryDesc(plan, pstate->p_sourcetext,
+		queryDesc = CreateQueryDesc(plan, NULL, pstate->p_sourcetext,
 									GetActiveSnapshot(), InvalidSnapshot,
 									dest, params, queryEnv, 0);
 
diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index 7e699f8595e..d6ab3697dd9 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -370,7 +370,7 @@ standard_ExplainOneQuery(Query *query, int cursorOptions,
 	}
 
 	/* run it (if needed) and produce output */
-	ExplainOnePlan(plan, into, es, queryString, params, queryEnv,
+	ExplainOnePlan(plan, NULL, into, es, queryString, params, queryEnv,
 				   &planduration, (es->buffers ? &bufusage : NULL),
 				   es->memory ? &mem_counters : NULL);
 }
@@ -492,7 +492,8 @@ ExplainOneUtility(Node *utilityStmt, IntoClause *into, ExplainState *es,
  * to call it.
  */
 void
-ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, ExplainState *es,
+ExplainOnePlan(PlannedStmt *plannedstmt, ExecPrep *prep,
+			   IntoClause *into, ExplainState *es,
 			   const char *queryString, ParamListInfo params,
 			   QueryEnvironment *queryEnv, const instr_time *planduration,
 			   const BufferUsage *bufusage,
@@ -548,7 +549,7 @@ ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, ExplainState *es,
 		dest = None_Receiver;
 
 	/* Create a QueryDesc for the query */
-	queryDesc = CreateQueryDesc(plannedstmt, queryString,
+	queryDesc = CreateQueryDesc(plannedstmt, prep, queryString,
 								GetActiveSnapshot(), InvalidSnapshot,
 								dest, params, queryEnv, instrument_option);
 
diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c
index 93ef1ad106f..3cca6d45ec1 100644
--- a/src/backend/commands/extension.c
+++ b/src/backend/commands/extension.c
@@ -993,6 +993,7 @@ execute_sql_string(const char *sql, const char *filename)
 				QueryDesc  *qdesc;
 
 				qdesc = CreateQueryDesc(stmt,
+										NULL,
 										sql,
 										GetActiveSnapshot(), NULL,
 										dest, NULL, NULL, 0);
diff --git a/src/backend/commands/matview.c b/src/backend/commands/matview.c
index ef7c0d624f1..30cbf9f264f 100644
--- a/src/backend/commands/matview.c
+++ b/src/backend/commands/matview.c
@@ -437,7 +437,7 @@ refresh_matview_datafill(DestReceiver *dest, Query *query,
 	UpdateActiveSnapshotCommandId();
 
 	/* Create a QueryDesc, redirecting output to our tuple receiver */
-	queryDesc = CreateQueryDesc(plan, queryString,
+	queryDesc = CreateQueryDesc(plan, NULL, queryString,
 								GetActiveSnapshot(), InvalidSnapshot,
 								dest, NULL, NULL, 0);
 
diff --git a/src/backend/commands/portalcmds.c b/src/backend/commands/portalcmds.c
index ec96c2efcd3..ac1ddd25aba 100644
--- a/src/backend/commands/portalcmds.c
+++ b/src/backend/commands/portalcmds.c
@@ -118,6 +118,7 @@ PerformCursorOpen(ParseState *pstate, DeclareCursorStmt *cstmt, ParamListInfo pa
 					  queryString,
 					  CMDTAG_SELECT,	/* cursor's query is always a SELECT */
 					  list_make1(plan),
+					  list_make1(NULL),
 					  NULL);
 
 	/*----------
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index 34b6410d6a2..afd449c73ba 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -205,6 +205,7 @@ ExecuteQuery(ParseState *pstate,
 					  query_string,
 					  entry->plansource->commandTag,
 					  plan_list,
+					  NIL,
 					  cplan);
 
 	/*
@@ -575,6 +576,7 @@ ExplainExecuteQuery(ExecuteStmt *execstmt, IntoClause *into, ExplainState *es,
 	const char *query_string;
 	CachedPlan *cplan;
 	List	   *plan_list;
+	List	   *prep_list;
 	ListCell   *p;
 	ParamListInfo paramLI = NULL;
 	EState	   *estate = NULL;
@@ -585,6 +587,7 @@ ExplainExecuteQuery(ExecuteStmt *execstmt, IntoClause *into, ExplainState *es,
 	MemoryContextCounters mem_counters;
 	MemoryContext planner_ctx = NULL;
 	MemoryContext saved_ctx = NULL;
+	int			i;
 
 	if (es->memory)
 	{
@@ -650,14 +653,20 @@ ExplainExecuteQuery(ExecuteStmt *execstmt, IntoClause *into, ExplainState *es,
 	}
 
 	plan_list = cplan->stmt_list;
+	prep_list = NIL;
 
 	/* Explain each query */
+	i = 0;
 	foreach(p, plan_list)
 	{
 		PlannedStmt *pstmt = lfirst_node(PlannedStmt, p);
+		ExecPrep *prep = prep_list ?
+			(ExecPrep *) list_nth(prep_list, i) : NULL;
 
+		i++;
 		if (pstmt->commandType != CMD_UTILITY)
-			ExplainOnePlan(pstmt, into, es, query_string, paramLI, pstate->p_queryEnv,
+			ExplainOnePlan(pstmt, prep,
+						   into, es, query_string, paramLI, pstate->p_queryEnv,
 						   &planduration, (es->buffers ? &bufusage : NULL),
 						   es->memory ? &mem_counters : NULL);
 		else
diff --git a/src/backend/executor/README b/src/backend/executor/README
index 54f4782f31b..95b5ec58c55 100644
--- a/src/backend/executor/README
+++ b/src/backend/executor/README
@@ -291,10 +291,16 @@ Query Processing Control Flow
 
 This is a sketch of control flow for full query processing:
 
+    ExecutorPrep
+		May be run before ExecutorStart (e.g., for plan validation), or
+		implicitly from ExecutorStart if not done earlier.  Performs range
+		table initialization, permission checks, and initial partition pruning.
+		Returns an ExecPrep wrapper with EState that ExecutorStart may reuse.
+
 	CreateQueryDesc
 
 	ExecutorStart
-		CreateExecutorState
+		CreateExecutorState (or reuse one from ExecPrep if present)
 			creates per-query context
 		switch to per-query context to run ExecInitNode
 		AfterTriggerBeginQuery
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 27c9eec697b..39de0b93a1c 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -171,8 +171,26 @@ standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
 
 	/*
 	 * Build EState, switch into per-query memory context for startup.
+	 *
+	 * If ExecutorPrep() ran earlier (e.g., to do initial pruning during plan
+	 * validity checking), reuse its EState to avoid redoing range table setup
+	 * and pruning. Otherwise, create a fresh EState as usual.
 	 */
-	estate = CreateExecutorState();
+	if (queryDesc->prep == NULL)
+		queryDesc->prep = ExecutorPrep(queryDesc->plannedstmt,
+									   queryDesc->params,
+									   CurrentResourceOwner,
+									   true,
+									   eflags);
+	Assert(queryDesc->prep);
+	estate = queryDesc->prep->prep_estate;
+
+	/*
+	 * Executor is adopting the prep's EState. Mark it so ExecPrepCleanup()
+	 * doesn't try to free it redundantly.
+	 */
+	queryDesc->prep->owns_estate = false;
+
 	queryDesc->estate = estate;
 
 	oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
@@ -263,6 +281,136 @@ standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
 	MemoryContextSwitchTo(oldcontext);
 }
 
+/*
+ * ExecutorPrep: prepare executor state for a PlannedStmt outside ExecutorStart.
+ *
+ * Performs range table initialization, permission checks, and initial
+ * partition pruning if partPruneInfos are present and do_initial_pruning is
+ * true.
+ *
+ * This is intended for callers that need executor metadata ahead of actual
+ * execution. Typical use cases include:
+ *	- determining which relations must be locked during plan cache validation;
+ *	- initializing unpruned relids and valid subplans in parallel workers
+ *	  using state copied from the leader.
+ *
+ * The executor can reuse the resulting state to avoid redundant setup during
+ * ExecutorStart().
+ *
+ * Returns an ExecPrep wrapper that owns the EState and can be reused
+ * or cleaned up later.
+ */
+ExecPrep *
+ExecutorPrep(PlannedStmt *pstmt, ParamListInfo params, ResourceOwner owner,
+			 bool do_initial_pruning, int eflags)
+{
+	ResourceOwner oldowner;
+	EState *estate;
+	bool	snapshot_set;
+
+	if (pstmt->commandType == CMD_UTILITY)
+		return NULL;
+
+	/* Pruning may use expressions that require an active snapshot. */
+	snapshot_set = false;
+	if (!ActiveSnapshotSet())
+	{
+		PushActiveSnapshot(GetTransactionSnapshot());
+		snapshot_set = true;
+	}
+	Assert(ActiveSnapshotSet());
+
+	estate = CreateExecutorState();
+	estate->es_plannedstmt = pstmt;
+	estate->es_part_prune_infos = pstmt->partPruneInfos;
+	estate->es_param_list_info = params;
+	estate->es_top_eflags = eflags;
+
+	/*
+	 * Do permissions checks.
+	 */
+	ExecCheckPermissions(pstmt->rtable, pstmt->permInfos, true);
+
+	/*
+	 * Initialize range table.
+	 */
+	ExecInitRangeTable(estate, pstmt->rtable, pstmt->permInfos,
+					   bms_copy(pstmt->unprunableRelids));
+
+	/*
+	 * Ensure locks taken during initial pruning are tracked under the given
+	 * ResourceOwner (e.g., one associated with CachedPlan validation).
+	 */
+	oldowner = CurrentResourceOwner;
+	CurrentResourceOwner = owner;
+
+	/*
+	 * Set up PartitionPruneState structures needed for both initial and
+	 * runtime partition pruning. These structures are built from the
+	 * PartitionPruneInfo entries in the plan tree.
+	 *
+	 * If do_initial_pruning is true, also perform initial pruning to compute
+	 * the subset of child subplans that will be executed. The results,
+	 * which are bitmapsets of selected child indexes, are saved in
+	 * es_part_prune_results. This list is parallel to es_part_prune_infos.
+	 *
+	 * In parallel workers, do_initial_pruning should be false -- they receive
+	 * es_part_prune_results from the leader process and should only initialize
+	 * the PartitionPruneStates.
+	 */
+	ExecCreatePartitionPruneStates(estate);
+	if (do_initial_pruning)
+		ExecDoInitialPruning(estate);
+
+	CurrentResourceOwner = oldowner;
+
+	/* Release snapshot if we got one */
+	if (snapshot_set)
+		PopActiveSnapshot();
+
+	return CreateExecPrep(estate, CurrentMemoryContext, NULL, NULL);
+}
+
+/*
+ * CreateExecPrep: initialize ExecPrep wrapper with optional cleanup metadata.
+ */
+ExecPrep *
+CreateExecPrep(EState *estate, MemoryContext context,
+			   execprep_cleanup_fn cleanup, void *cleanup_arg)
+{
+	ExecPrep *prep = palloc0(sizeof(ExecPrep));
+
+	prep->prep_estate = estate;
+	prep->context = context;
+	prep->cleanup = cleanup;
+	prep->cleanup_arg = cleanup_arg;
+	prep->owns_estate = true;
+
+	return prep;
+}
+
+/*
+ * ExecPrepCleanup: free ExecPrep resources not adopted by the executor.
+ *
+ * Only frees the EState if it wasn't taken over by ExecutorStart().
+ * Always runs the optional user-defined cleanup callback.
+ */
+void
+ExecPrepCleanup(ExecPrep *prep)
+{
+	if (prep == NULL)
+		return;
+
+	if (prep->prep_estate && prep->owns_estate)
+	{
+		ExecCloseRangeTableRelations(prep->prep_estate);
+		FreeExecutorState(prep->prep_estate);
+	}
+
+	if (prep->cleanup)
+		prep->cleanup(prep->cleanup_arg);
+}
+
 /* ----------------------------------------------------------------
  *		ExecutorRun
  *
@@ -824,7 +972,6 @@ ExecCheckXactReadOnly(PlannedStmt *plannedstmt)
 		PreventCommandIfParallelMode(CreateCommandName((Node *) plannedstmt));
 }
 
-
 /* ----------------------------------------------------------------
  *		InitPlan
  *
@@ -838,37 +985,15 @@ InitPlan(QueryDesc *queryDesc, int eflags)
 	CmdType		operation = queryDesc->operation;
 	PlannedStmt *plannedstmt = queryDesc->plannedstmt;
 	Plan	   *plan = plannedstmt->planTree;
-	List	   *rangeTable = plannedstmt->rtable;
 	EState	   *estate = queryDesc->estate;
 	PlanState  *planstate;
 	TupleDesc	tupType;
 	ListCell   *l;
 	int			i;
 
-	/*
-	 * Do permissions checks
-	 */
-	ExecCheckPermissions(rangeTable, plannedstmt->permInfos, true);
-
-	/*
-	 * initialize the node's execution state
-	 */
-	ExecInitRangeTable(estate, rangeTable, plannedstmt->permInfos,
-					   bms_copy(plannedstmt->unprunableRelids));
-
-	estate->es_plannedstmt = plannedstmt;
-	estate->es_part_prune_infos = plannedstmt->partPruneInfos;
-
-	/*
-	 * Perform runtime "initial" pruning to identify which child subplans,
-	 * corresponding to the children of plan nodes that contain
-	 * PartitionPruneInfo such as Append, will not be executed. The results,
-	 * which are bitmapsets of indexes of the child subplans that will be
-	 * executed, are saved in es_part_prune_results.  These results correspond
-	 * to each PartitionPruneInfo entry, and the es_part_prune_results list is
-	 * parallel to es_part_prune_infos.
-	 */
-	ExecDoInitialPruning(estate);
+	/* ExecutorPrep() must have been done. */
+	Assert(queryDesc->prep);
+	Assert(estate == queryDesc->prep->prep_estate);
 
 	/*
 	 * Next, build the ExecRowMark array from the PlanRowMark(s), if any.
diff --git a/src/backend/executor/execParallel.c b/src/backend/executor/execParallel.c
index f098a5557cf..aedbd9566d6 100644
--- a/src/backend/executor/execParallel.c
+++ b/src/backend/executor/execParallel.c
@@ -1281,6 +1281,7 @@ ExecParallelGetQueryDesc(shm_toc *toc, DestReceiver *receiver,
 
 	/* Create a QueryDesc for the query. */
 	return CreateQueryDesc(pstmt,
+						   NULL,
 						   queryString,
 						   GetActiveSnapshot(), InvalidSnapshot,
 						   receiver, paramLI, NULL, instrument_options);
diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
index 88b150c8d77..187a480e508 100644
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -2368,6 +2368,9 @@ InitExecPartitionPruneContexts(PartitionPruneState *prunestate,
 	Assert(parent_plan != NULL);
 	estate = parent_plan->state;
 
+	/* Wouldn't be available at ExecutorPrep() time. */
+	prunestate->econtext->ecxt_param_exec_vals = estate->es_param_exec_vals;
+
 	/*
 	 * No need to fix subplans maps if initial pruning didn't eliminate any
 	 * subplans.
diff --git a/src/backend/executor/functions.c b/src/backend/executor/functions.c
index 630d708d2a3..633310c5f5b 100644
--- a/src/backend/executor/functions.c
+++ b/src/backend/executor/functions.c
@@ -1362,6 +1362,7 @@ postquel_start(execution_state *es, SQLFunctionCachePtr fcache)
 		dest = None_Receiver;
 
 	es->qd = CreateQueryDesc(es->stmt,
+							 NULL,
 							 fcache->func->src,
 							 GetActiveSnapshot(),
 							 InvalidSnapshot,
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index 653500b38dc..7a3cb944d6f 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -1685,6 +1685,7 @@ SPI_cursor_open_internal(const char *name, SPIPlanPtr plan,
 					  query_string,
 					  plansource->commandTag,
 					  stmt_list,
+					  NIL,
 					  cplan);
 
 	/*
@@ -2500,6 +2501,8 @@ _SPI_execute_plan(SPIPlanPtr plan, const SPIExecuteOptions *options,
 		CachedPlanSource *plansource = (CachedPlanSource *) lfirst(lc1);
 		List	   *stmt_list;
 		ListCell   *lc2;
+		List	   *prep_list;
+		int			i;
 
 		spicallbackarg.query = plansource->query_string;
 
@@ -2578,6 +2581,7 @@ _SPI_execute_plan(SPIPlanPtr plan, const SPIExecuteOptions *options,
 							  plan_owner, _SPI_current->queryEnv);
 
 		stmt_list = cplan->stmt_list;
+		prep_list = NIL;
 
 		/*
 		 * If we weren't given a specific snapshot to use, and the statement
@@ -2615,12 +2619,17 @@ _SPI_execute_plan(SPIPlanPtr plan, const SPIExecuteOptions *options,
 			}
 		}
 
+		i = 0;
 		foreach(lc2, stmt_list)
 		{
 			PlannedStmt *stmt = lfirst_node(PlannedStmt, lc2);
+			ExecPrep *prep = prep_list ?
+				list_nth(prep_list, i) : NULL;
 			bool		canSetTag = stmt->canSetTag;
 			DestReceiver *dest;
 
+			i++;
+
 			/*
 			 * Reset output state.  (Note that if a non-SPI receiver is used,
 			 * _SPI_current->processed will stay zero, and that's what we'll
@@ -2690,6 +2699,7 @@ _SPI_execute_plan(SPIPlanPtr plan, const SPIExecuteOptions *options,
 					snap = InvalidSnapshot;
 
 				qdesc = CreateQueryDesc(stmt,
+										prep,
 										plansource->query_string,
 										snap, crosscheck_snapshot,
 										dest,
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 2bd89102686..d3964a12a14 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -1232,6 +1232,7 @@ exec_simple_query(const char *query_string)
 						  query_string,
 						  commandTag,
 						  plantree_list,
+						  NIL,
 						  NULL);
 
 		/*
@@ -2033,6 +2034,7 @@ exec_bind_message(StringInfo input_message)
 					  query_string,
 					  psrc->commandTag,
 					  cplan->stmt_list,
+					  NIL,
 					  cplan);
 
 	/* Portal is defined, set the plan ID based on its contents. */
diff --git a/src/backend/tcop/pquery.c b/src/backend/tcop/pquery.c
index fde78c55160..82c295502b0 100644
--- a/src/backend/tcop/pquery.c
+++ b/src/backend/tcop/pquery.c
@@ -37,6 +37,7 @@ Portal		ActivePortal = NULL;
 
 
 static void ProcessQuery(PlannedStmt *plan,
+						 ExecPrep *prep,
 						 const char *sourceText,
 						 ParamListInfo params,
 						 QueryEnvironment *queryEnv,
@@ -66,6 +67,7 @@ static void DoPortalRewind(Portal portal);
  */
 QueryDesc *
 CreateQueryDesc(PlannedStmt *plannedstmt,
+				ExecPrep *prep,
 				const char *sourceText,
 				Snapshot snapshot,
 				Snapshot crosscheck_snapshot,
@@ -78,6 +80,7 @@ CreateQueryDesc(PlannedStmt *plannedstmt,
 
 	qd->operation = plannedstmt->commandType;	/* operation */
 	qd->plannedstmt = plannedstmt;	/* plan */
+	qd->prep = prep;		/* executor prep output */
 	qd->sourceText = sourceText;	/* query text */
 	qd->snapshot = RegisterSnapshot(snapshot);	/* snapshot */
 	/* RI check snapshot */
@@ -112,6 +115,13 @@ FreeQueryDesc(QueryDesc *qdesc)
 	UnregisterSnapshot(qdesc->snapshot);
 	UnregisterSnapshot(qdesc->crosscheck_snapshot);
 
+	/* ExecPrep cleanup if necessary */
+	if (qdesc->prep)
+	{
+		ExecPrepCleanup(qdesc->prep);
+		qdesc->prep = NULL;
+	}
+
 	/* Only the QueryDesc itself need be freed */
 	pfree(qdesc);
 }
@@ -123,6 +133,7 @@ FreeQueryDesc(QueryDesc *qdesc)
  *		PORTAL_ONE_RETURNING, or PORTAL_ONE_MOD_WITH portal
  *
  *	plan: the plan tree for the query
+ *	prep: ExecPrep for the plan (output of ExecutorPrep())
  *	sourceText: the source text of the query
  *	params: any parameters needed
  *	dest: where to send results
@@ -135,6 +146,7 @@ FreeQueryDesc(QueryDesc *qdesc)
  */
 static void
 ProcessQuery(PlannedStmt *plan,
+			 ExecPrep *prep,
 			 const char *sourceText,
 			 ParamListInfo params,
 			 QueryEnvironment *queryEnv,
@@ -146,7 +158,7 @@ ProcessQuery(PlannedStmt *plan,
 	/*
 	 * Create the QueryDesc object
 	 */
-	queryDesc = CreateQueryDesc(plan, sourceText,
+	queryDesc = CreateQueryDesc(plan, prep, sourceText,
 								GetActiveSnapshot(), InvalidSnapshot,
 								dest, params, queryEnv, 0);
 
@@ -489,6 +501,9 @@ PortalStart(Portal portal, ParamListInfo params,
 				 * the destination to DestNone.
 				 */
 				queryDesc = CreateQueryDesc(linitial_node(PlannedStmt, portal->stmts),
+											portal->preps ?
+											(ExecPrep *) linitial(portal->preps) :
+											NULL,
 											portal->sourceText,
 											GetActiveSnapshot(),
 											InvalidSnapshot,
@@ -1185,6 +1200,7 @@ PortalRunMulti(Portal portal,
 {
 	bool		active_snapshot_set = false;
 	ListCell   *stmtlist_item;
+	int			i;
 
 	/*
 	 * If the destination is DestRemoteExecute, change to DestNone.  The
@@ -1205,9 +1221,14 @@ PortalRunMulti(Portal portal,
 	 * Loop to handle the individual queries generated from a single parsetree
 	 * by analysis and rewrite.
 	 */
+	i = 0;
 	foreach(stmtlist_item, portal->stmts)
 	{
 		PlannedStmt *pstmt = lfirst_node(PlannedStmt, stmtlist_item);
+		ExecPrep *prep = portal->preps ?
+			list_nth(portal->preps, i) : NULL;
+
+		i++;
 
 		/*
 		 * If we got a cancel signal in prior command, quit
@@ -1265,7 +1286,7 @@ PortalRunMulti(Portal portal,
 			if (pstmt->canSetTag)
 			{
 				/* statement can set tag string */
-				ProcessQuery(pstmt,
+				ProcessQuery(pstmt, prep,
 							 portal->sourceText,
 							 portal->portalParams,
 							 portal->queryEnv,
@@ -1274,7 +1295,7 @@ PortalRunMulti(Portal portal,
 			else
 			{
 				/* stmt added by rewrite cannot set tag */
-				ProcessQuery(pstmt,
+				ProcessQuery(pstmt, prep,
 							 portal->sourceText,
 							 portal->portalParams,
 							 portal->queryEnv,
diff --git a/src/backend/utils/mmgr/portalmem.c b/src/backend/utils/mmgr/portalmem.c
index 943da087c9f..313f8ef2fdc 100644
--- a/src/backend/utils/mmgr/portalmem.c
+++ b/src/backend/utils/mmgr/portalmem.c
@@ -284,6 +284,7 @@ PortalDefineQuery(Portal portal,
 				  const char *sourceText,
 				  CommandTag commandTag,
 				  List *stmts,
+				  List *preps,
 				  CachedPlan *cplan)
 {
 	Assert(PortalIsValid(portal));
@@ -298,6 +299,7 @@ PortalDefineQuery(Portal portal,
 	portal->qc.nprocessed = 0;
 	portal->commandTag = commandTag;
 	portal->stmts = stmts;
+	portal->preps = preps;
 	portal->cplan = cplan;
 	portal->status = PORTAL_DEFINED;
 }
diff --git a/src/include/commands/explain.h b/src/include/commands/explain.h
index 6e51d50efc7..6aa8b275aa2 100644
--- a/src/include/commands/explain.h
+++ b/src/include/commands/explain.h
@@ -63,7 +63,8 @@ extern void ExplainOneUtility(Node *utilityStmt, IntoClause *into,
 							  ExplainState *es, ParseState *pstate,
 							  ParamListInfo params);
 
-extern void ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into,
+extern void ExplainOnePlan(PlannedStmt *plannedstmt, ExecPrep *prep,
+						   IntoClause *into,
 						   ExplainState *es, const char *queryString,
 						   ParamListInfo params, QueryEnvironment *queryEnv,
 						   const instr_time *planduration,
diff --git a/src/include/executor/execdesc.h b/src/include/executor/execdesc.h
index 86db3dc8d0d..c18530f5d11 100644
--- a/src/include/executor/execdesc.h
+++ b/src/include/executor/execdesc.h
@@ -18,7 +18,6 @@
 #include "nodes/execnodes.h"
 #include "tcop/dest.h"
 
-
 /* ----------------
  *		query descriptor:
  *
@@ -35,6 +34,7 @@ typedef struct QueryDesc
 	/* These fields are provided by CreateQueryDesc */
 	CmdType		operation;		/* CMD_SELECT, CMD_UPDATE, etc. */
 	PlannedStmt *plannedstmt;	/* planner's output (could be utility, too) */
+	ExecPrep *prep;				/* output of ExecutorPrep() or NULL */
 	const char *sourceText;		/* source text of the query */
 	Snapshot	snapshot;		/* snapshot to use for query */
 	Snapshot	crosscheck_snapshot;	/* crosscheck for RI update/delete */
@@ -57,6 +57,7 @@ typedef struct QueryDesc
 
 /* in pquery.c */
 extern QueryDesc *CreateQueryDesc(PlannedStmt *plannedstmt,
+								  ExecPrep *prep,
 								  const char *sourceText,
 								  Snapshot snapshot,
 								  Snapshot crosscheck_snapshot,
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
index fa2b657fb2f..3579926d4e8 100644
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -20,6 +20,7 @@
 #include "nodes/lockoptions.h"
 #include "nodes/parsenodes.h"
 #include "utils/memutils.h"
+#include "utils/resowner.h"
 
 
 /*
@@ -234,6 +235,16 @@ ExecGetJunkAttribute(TupleTableSlot *slot, AttrNumber attno, bool *isNull)
  */
 extern void ExecutorStart(QueryDesc *queryDesc, int eflags);
 extern void standard_ExecutorStart(QueryDesc *queryDesc, int eflags);
+
+extern ExecPrep *ExecutorPrep(PlannedStmt *pstmt,
+							  ParamListInfo params,
+							  ResourceOwner owner,
+							  bool do_initial_pruning,
+							  int eflags);
+extern ExecPrep *CreateExecPrep(EState *estate, MemoryContext context,
+								execprep_cleanup_fn cleanup, void *cleanup_arg);
+extern void ExecPrepCleanup(ExecPrep *prep);
+
 extern void ExecutorRun(QueryDesc *queryDesc,
 						ScanDirection direction, uint64 count);
 extern void standard_ExecutorRun(QueryDesc *queryDesc,
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 18ae8f0d4bb..8bdecd631bf 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -772,6 +772,54 @@ typedef struct EState
 	List	   *es_insert_pending_modifytables;
 } EState;
 
+/*
+ * ExecPrep: encapsulates executor preparation results for a PlannedStmt.
+ *
+ * ExecutorPrep() factors out executor setup steps such as initializing the
+ * range table, checking permissions, and executing initial partition pruning.
+ * ExecutorStart() can reuse the prepared EState instead of repeating that
+ * work, and other callers (such as plan cache validation) can use it without
+ * running the full plan.
+ */
+
+/*
+ * Optional callback to clean up user-specific resources associated with
+ * ExecPrep.
+ */
+typedef void (*execprep_cleanup_fn)(void *prep);
+
+typedef struct ExecPrep
+{
+	/*
+	 * Context in which this struct and all subsidiary allocations were made.
+	 * This context must remain alive until ExecPrepCleanup is called.
+	 */
+	MemoryContext context;
+
+	/*
+	 * Partially-initialized executor state used for permission checks and
+	 * pruning. May be adopted directly by ExecutorStart(), in which case
+	 * ExecPrepCleanup will skip freeing it.
+	 */
+	EState	   *prep_estate;
+
+	/*
+	 * True if ExecPrepCleanup() must free the EState.  If the executor adopts
+	 * prep_estate, this is set to false to avoid double-free.
+	 */
+	bool		owns_estate;
+
+	/*
+	 * Optional caller-supplied cleanup hook to run during ExecPrepCleanup.
+	 * Useful for releasing external resources associated with the prep.
+	 */
+	execprep_cleanup_fn cleanup;
+
+	/*
+	 * Opaque pointer to pass to the cleanup hook.
+	 */
+	void	   *cleanup_arg;
+} ExecPrep;
 
 /*
  * ExecRowMark -
diff --git a/src/include/utils/portal.h b/src/include/utils/portal.h
index 5ffa6fd5cc8..013bcc3bd8e 100644
--- a/src/include/utils/portal.h
+++ b/src/include/utils/portal.h
@@ -137,6 +137,7 @@ typedef struct PortalData
 	CommandTag	commandTag;		/* command tag for original query */
 	QueryCompletion qc;			/* command completion data for executed query */
 	List	   *stmts;			/* list of PlannedStmts */
+	List	   *preps;			/* list of ExecPreps where needed */
 	CachedPlan *cplan;			/* CachedPlan, if stmts are from one */
 
 	ParamListInfo portalParams; /* params to pass to query */
@@ -240,6 +241,7 @@ extern void PortalDefineQuery(Portal portal,
 							  const char *sourceText,
 							  CommandTag commandTag,
 							  List *stmts,
+							  List *preps,
 							  CachedPlan *cplan);
 extern PlannedStmt *PortalGetPrimaryStmt(Portal portal);
 extern void PortalCreateHoldStore(Portal portal);
-- 
2.47.3

