YOLO

README.md

-# CS631-Project
+# CS631-Project: Automatic Index creation in postgres.
 
+***Authors** @meet.doshi @gaurangathavale @jiteshg*
+
+---
+
+#### For checking patch updates 
+```
+Just look at the following files
+execMain.c
+nodeSeqScan.c
+worker_spi/worker_spi.c
+Makefile
+
+Look for following tags
+/* CS631 start */
+/* CS631 end */
+```
+
+###File Structure:
+
+```
+<22m0742_22m0752>
+├── execMain.c ~ User queries without where clause dont reach node sequential scan level. So they have to be stored at execMain level. Currently we are only saving insert and delete queries.
+├── nodeSeqScan.c ~ Operates at table level. Here we are keeping track of all select queries with and without where clause.
+├── worker_spi/ ~ This module should be registered in contrib folder and requires updates in the make file in same folder.
+│   ├── worker_spi.c ~ This is the daemon process which runs every 20 seconds. It alternates with a toggle where first time it fetches info and decides which index to create. On the next round it executes the query and creates the index.
+└── readme.md
+
+```
+
+
+###Tasks:
+
+1. Storing logs of incoming user queries for later use on making a decision whether to create an index or not.
+2. Creating a daemon process like a cron job for the database which runs regularly to check whether indexes need to be created or not.
+3. Building up logic for the daemon process to decided whether indexes need to be created or deleted.
+
+###Cautions:
+1. Installing worker module correctly and updating makefiles.
+2. Accessing uninitialized or modifying static memory.
+3. Recursive loops inside code.
+4. Codebase changes due to changes in postgres versions. So be sure to check if the data structures and libraries are matching. 
+5. Mutliple where clauses and subqueries.
+6. Current postgres version 13.7 `Different from the git version`
\ No newline at end of file

execMain.c

+/*-------------------------------------------------------------------------
+ *
+ * execMain.c
+ *	  top level executor interface routines
+ *
+ * INTERFACE ROUTINES
+ *	ExecutorStart()
+ *	ExecutorRun()
+ *	ExecutorFinish()
+ *	ExecutorEnd()
+ *
+ *	These four procedures are the external interface to the executor.
+ *	In each case, the query descriptor is required as an argument.
+ *
+ *	ExecutorStart must be called at the beginning of execution of any
+ *	query plan and ExecutorEnd must always be called at the end of
+ *	execution of a plan (unless it is aborted due to error).
+ *
+ *	ExecutorRun accepts direction and count arguments that specify whether
+ *	the plan is to be executed forwards, backwards, and for how many tuples.
+ *	In some cases ExecutorRun may be called multiple times to process all
+ *	the tuples for a plan.  It is also acceptable to stop short of executing
+ *	the whole plan (but only if it is a SELECT).
+ *
+ *	ExecutorFinish must be called after the final ExecutorRun call and
+ *	before ExecutorEnd.  This can be omitted only in case of EXPLAIN,
+ *	which should also omit ExecutorRun.
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/executor/execMain.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/heapam.h"
+#include "access/htup_details.h"
+#include "access/sysattr.h"
+#include "access/tableam.h"
+#include "access/transam.h"
+#include "access/xact.h"
+#include "catalog/namespace.h"
+#include "catalog/pg_publication.h"
+#include "commands/matview.h"
+#include "commands/trigger.h"
+#include "executor/execdebug.h"
+#include "executor/nodeSubplan.h"
+#include "foreign/fdwapi.h"
+#include "jit/jit.h"
+#include "mb/pg_wchar.h"
+#include "miscadmin.h"
+#include "parser/parsetree.h"
+#include "storage/bufmgr.h"
+#include "storage/lmgr.h"
+#include "tcop/utility.h"
+#include "utils/acl.h"
+#include "utils/backend_status.h"
+#include "utils/lsyscache.h"
+#include "utils/memutils.h"
+#include "utils/partcache.h"
+#include "utils/rls.h"
+#include "utils/ruleutils.h"
+#include "utils/snapmgr.h"
+/* CS631 start */
+#include "executor/spi.h"
+/* CS631 end */
+
+
+/* Hooks for plugins to get control in ExecutorStart/Run/Finish/End */
+ExecutorStart_hook_type ExecutorStart_hook = NULL;
+ExecutorRun_hook_type ExecutorRun_hook = NULL;
+ExecutorFinish_hook_type ExecutorFinish_hook = NULL;
+ExecutorEnd_hook_type ExecutorEnd_hook = NULL;
+
+/* Hook for plugin to get control in ExecCheckRTPerms() */
+ExecutorCheckPerms_hook_type ExecutorCheckPerms_hook = NULL;
+
+/* decls for local routines only used within this module */
+static void InitPlan(QueryDesc *queryDesc, int eflags);
+static void CheckValidRowMarkRel(Relation rel, RowMarkType markType);
+static void ExecPostprocessPlan(EState *estate);
+static void ExecEndPlan(PlanState *planstate, EState *estate);
+static void ExecutePlan(EState *estate, PlanState *planstate,
+						bool use_parallel_mode,
+						CmdType operation,
+						bool sendTuples,
+						uint64 numberTuples,
+						ScanDirection direction,
+						DestReceiver *dest,
+						bool execute_once);
+static bool ExecCheckRTEPerms(RangeTblEntry *rte);
+static bool ExecCheckRTEPermsModified(Oid relOid, Oid userid,
+									  Bitmapset *modifiedCols,
+									  AclMode requiredPerms);
+static void ExecCheckXactReadOnly(PlannedStmt *plannedstmt);
+static char *ExecBuildSlotValueDescription(Oid reloid,
+										   TupleTableSlot *slot,
+										   TupleDesc tupdesc,
+										   Bitmapset *modifiedCols,
+										   int maxfieldlen);
+static void EvalPlanQualStart(EPQState *epqstate, Plan *planTree);
+
+/* end of local decls */
+
+
+/* ----------------------------------------------------------------
+ *		ExecutorStart
+ *
+ *		This routine must be called at the beginning of any execution of any
+ *		query plan
+ *
+ * Takes a QueryDesc previously created by CreateQueryDesc (which is separate
+ * only because some places use QueryDescs for utility commands).  The tupDesc
+ * field of the QueryDesc is filled in to describe the tuples that will be
+ * returned, and the internal fields (estate and planstate) are set up.
+ *
+ * eflags contains flag bits as described in executor.h.
+ *
+ * NB: the CurrentMemoryContext when this is called will become the parent
+ * of the per-query context used for this Executor invocation.
+ *
+ * We provide a function hook variable that lets loadable plugins
+ * get control when ExecutorStart is called.  Such a plugin would
+ * normally call standard_ExecutorStart().
+ *
+ * ----------------------------------------------------------------
+ */
+void
+ExecutorStart(QueryDesc *queryDesc, int eflags)
+{
+	/*
+	 * In some cases (e.g. an EXECUTE statement) a query execution will skip
+	 * parse analysis, which means that the query_id won't be reported.  Note
+	 * that it's harmless to report the query_id multiple time, as the call
+	 * will be ignored if the top level query_id has already been reported.
+	 */
+	pgstat_report_query_id(queryDesc->plannedstmt->queryId, false);
+
+	if (ExecutorStart_hook)
+		(*ExecutorStart_hook) (queryDesc, eflags);
+	else
+		standard_ExecutorStart(queryDesc, eflags);
+}
+
+void
+standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
+{
+	EState	   *estate;
+	MemoryContext oldcontext;
+
+	/* sanity checks: queryDesc must not be started already */
+	Assert(queryDesc != NULL);
+	Assert(queryDesc->estate == NULL);
+
+	/*
+	 * If the transaction is read-only, we need to check if any writes are
+	 * planned to non-temporary tables.  EXPLAIN is considered read-only.
+	 *
+	 * Don't allow writes in parallel mode.  Supporting UPDATE and DELETE
+	 * would require (a) storing the combo CID hash in shared memory, rather
+	 * than synchronizing it just once at the start of parallelism, and (b) an
+	 * alternative to heap_update()'s reliance on xmax for mutual exclusion.
+	 * INSERT may have no such troubles, but we forbid it to simplify the
+	 * checks.
+	 *
+	 * We have lower-level defenses in CommandCounterIncrement and elsewhere
+	 * against performing unsafe operations in parallel mode, but this gives a
+	 * more user-friendly error message.
+	 */
+	if ((XactReadOnly || IsInParallelMode()) &&
+		!(eflags & EXEC_FLAG_EXPLAIN_ONLY))
+		ExecCheckXactReadOnly(queryDesc->plannedstmt);
+
+	/*
+	 * Build EState, switch into per-query memory context for startup.
+	 */
+	estate = CreateExecutorState();
+	queryDesc->estate = estate;
+
+	oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
+
+	/*
+	 * Fill in external parameters, if any, from queryDesc; and allocate
+	 * workspace for internal parameters
+	 */
+	estate->es_param_list_info = queryDesc->params;
+
+	if (queryDesc->plannedstmt->paramExecTypes != NIL)
+	{
+		int			nParamExec;
+
+		nParamExec = list_length(queryDesc->plannedstmt->paramExecTypes);
+		estate->es_param_exec_vals = (ParamExecData *)
+			palloc0(nParamExec * sizeof(ParamExecData));
+	}
+
+	/* We now require all callers to provide sourceText */
+	Assert(queryDesc->sourceText != NULL);
+	estate->es_sourceText = queryDesc->sourceText;
+
+	/*
+	 * Fill in the query environment, if any, from queryDesc.
+	 */
+	estate->es_queryEnv = queryDesc->queryEnv;
+
+	/*
+	 * If non-read-only query, set the command ID to mark output tuples with
+	 */
+	switch (queryDesc->operation)
+	{
+		case CMD_SELECT:
+
+			/*
+			 * SELECT FOR [KEY] UPDATE/SHARE and modifying CTEs need to mark
+			 * tuples
+			 */
+			if (queryDesc->plannedstmt->rowMarks != NIL ||
+				queryDesc->plannedstmt->hasModifyingCTE)
+				estate->es_output_cid = GetCurrentCommandId(true);
+
+			/*
+			 * A SELECT without modifying CTEs can't possibly queue triggers,
+			 * so force skip-triggers mode. This is just a marginal efficiency
+			 * hack, since AfterTriggerBeginQuery/AfterTriggerEndQuery aren't
+			 * all that expensive, but we might as well do it.
+			 */
+			if (!queryDesc->plannedstmt->hasModifyingCTE)
+				eflags |= EXEC_FLAG_SKIP_TRIGGERS;
+			break;
+
+		case CMD_INSERT:
+		case CMD_DELETE:
+		case CMD_UPDATE:
+			estate->es_output_cid = GetCurrentCommandId(true);
+			break;
+
+		default:
+			elog(ERROR, "unrecognized operation code: %d",
+				 (int) queryDesc->operation);
+			break;
+	}
+
+	/*
+	 * Copy other important information into the EState
+	 */
+	estate->es_snapshot = RegisterSnapshot(queryDesc->snapshot);
+	estate->es_crosscheck_snapshot = RegisterSnapshot(queryDesc->crosscheck_snapshot);
+	estate->es_top_eflags = eflags;
+	estate->es_instrument = queryDesc->instrument_options;
+	estate->es_jit_flags = queryDesc->plannedstmt->jitFlags;
+
+	/*
+	 * Set up an AFTER-trigger statement context, unless told not to, or
+	 * unless it's EXPLAIN-only mode (when ExecutorFinish won't be called).
+	 */
+	if (!(eflags & (EXEC_FLAG_SKIP_TRIGGERS | EXEC_FLAG_EXPLAIN_ONLY)))
+		AfterTriggerBeginQuery();
+
+	/*
+	 * Initialize the plan state tree
+	 */
+	InitPlan(queryDesc, eflags);
+
+/* CS631 start */
+	char	   *s;
+	char	   *f;
+	ListCell* temp;
+	Alias* eref_val;
+	List* col_names;
+	char* relName;
+	int ret;
+	char *type;
+	char attrs[100] = "";
+	char *add1 = "','";
+	char *add2 = "','";
+	char *add3 = "');";
+	char new_new_query[200] = "INSERT INTO AIDX_QUERIES VALUES('";
+
+	relName = estate->es_relations[0]->rd_rel->relname.data;
+	elog(LOG,"%s TABLE NAME FROM INSERT\n",relName);
+
+	if(CMD_INSERT == queryDesc->plannedstmt->commandType)
+	 type = "insert";
+
+	/* This will only run when insert is not done on aidx_queries as it cannot be updated by user
+	 * Hence the if condition will break the recursive calls
+	 * And this flow needs to be run only for inserts, hence the other CMDType check
+	 */
+
+	if(strcmp("aidx_queries",relName) && CMD_INSERT == queryDesc->plannedstmt->commandType){
+	int i1;
+	attrs[0] = '*';
+
+	/* Creating the insert into aidx_queries query */
+
+	int j1 = strlen(new_new_query);
+
+	for (i1 = 0; type[i1] != '\0'; i1++) {
+		new_new_query[i1 + j1] = type[i1];
+	}
+
+	j1 = strlen(new_new_query);
+
+	for (i1 = 0; add1[i1] != '\0'; i1++) {
+			new_new_query[i1 + j1] = add1[i1];
+	}
+
+	j1 = strlen(new_new_query);
+
+	for (i1 = 0; relName[i1] != '\0'; i1++) {
+			new_new_query[i1 + j1] = relName[i1];
+	}
+
+	j1 = strlen(new_new_query);
+
+	for (i1 = 0; add2[i1] != '\0'; i1++) {
+			new_new_query[i1 + j1] = add2[i1];
+	}
+
+	j1 = strlen(new_new_query);
+
+	for (i1 = 0; attrs[i1] != '\0'; i1++) {
+			new_new_query[i1 + j1] = attrs[i1];
+	}
+
+	j1 = strlen(new_new_query);
+
+	for (i1 = 0; add3[i1] != '\0'; i1++) {
+			new_new_query[i1 + j1] = add3[i1];
+	}
+
+	new_new_query[i1 + j1] = '\0';
+
+	elog(LOG, "%s", new_new_query);
+
+	 if( SPI_connect() == SPI_OK_CONNECT )
+		{
+			ret = SPI_execute(new_new_query,false,0);
+			ret = SPI_finish();
+		}
+	 }
+/* CS631 end */
+
+
+	MemoryContextSwitchTo(oldcontext);
+}
+
+/* ----------------------------------------------------------------
+ *		ExecutorRun
+ *
+ *		This is the main routine of the executor module. It accepts
+ *		the query descriptor from the traffic cop and executes the
+ *		query plan.
+ *
+ *		ExecutorStart must have been called already.
+ *
+ *		If direction is NoMovementScanDirection then nothing is done
+ *		except to start up/shut down the destination.  Otherwise,
+ *		we retrieve up to 'count' tuples in the specified direction.
+ *
+ *		Note: count = 0 is interpreted as no portal limit, i.e., run to
+ *		completion.  Also note that the count limit is only applied to
+ *		retrieved tuples, not for instance to those inserted/updated/deleted
+ *		by a ModifyTable plan node.
+ *
+ *		There is no return value, but output tuples (if any) are sent to
+ *		the destination receiver specified in the QueryDesc; and the number
+ *		of tuples processed at the top level can be found in
+ *		estate->es_processed.
+ *
+ *		We provide a function hook variable that lets loadable plugins
+ *		get control when ExecutorRun is called.  Such a plugin would
+ *		normally call standard_ExecutorRun().
+ *
+ * ----------------------------------------------------------------
+ */
+void
+ExecutorRun(QueryDesc *queryDesc,
+			ScanDirection direction, uint64 count,
+			bool execute_once)
+{
+	if (ExecutorRun_hook)
+		(*ExecutorRun_hook) (queryDesc, direction, count, execute_once);
+	else
+		standard_ExecutorRun(queryDesc, direction, count, execute_once);
+}
+
+void
+standard_ExecutorRun(QueryDesc *queryDesc,
+					 ScanDirection direction, uint64 count, bool execute_once)
+{
+	EState	   *estate;
+	CmdType		operation;
+	DestReceiver *dest;
+	bool		sendTuples;
+	MemoryContext oldcontext;
+
+	/* sanity checks */
+	Assert(queryDesc != NULL);
+
+	estate = queryDesc->estate;
+
+	Assert(estate != NULL);
+	Assert(!(estate->es_top_eflags & EXEC_FLAG_EXPLAIN_ONLY));
+
+	/*
+	 * Switch into per-query memory context
+	 */
+	oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
+
+	/* Allow instrumentation of Executor overall runtime */
+	if (queryDesc->totaltime)
+		InstrStartNode(queryDesc->totaltime);
+
+	/*
+	 * extract information from the query descriptor and the query feature.
+	 */
+	operation = queryDesc->operation;
+	dest = queryDesc->dest;
+
+	/*
+	 * startup tuple receiver, if we will be emitting tuples
+	 */
+	estate->es_processed = 0;
+
+	sendTuples = (operation == CMD_SELECT ||
+				  queryDesc->plannedstmt->hasReturning);
+
+	if (sendTuples)
+		dest->rStartup(dest, operation, queryDesc->tupDesc);
+
+	/*
+	 * run plan
+	 */
+	if (!ScanDirectionIsNoMovement(direction))
+	{
+		if (execute_once && queryDesc->already_executed)
+			elog(ERROR, "can't re-execute query flagged for single execution");
+		queryDesc->already_executed = true;
+
+		ExecutePlan(estate,
+					queryDesc->planstate,
+					queryDesc->plannedstmt->parallelModeNeeded,
+					operation,
+					sendTuples,
+					count,
+					direction,
+					dest,
+					execute_once);
+	}
+
+	/*
+	 * shutdown tuple receiver, if we started it
+	 */
+	if (sendTuples)
+		dest->rShutdown(dest);
+
+	if (queryDesc->totaltime)
+		InstrStopNode(queryDesc->totaltime, estate->es_processed);
+
+	MemoryContextSwitchTo(oldcontext);
+}
+
+/* ----------------------------------------------------------------
+ *		ExecutorFinish
+ *
+ *		This routine must be called after the last ExecutorRun call.
+ *		It performs cleanup such as firing AFTER triggers.  It is
+ *		separate from ExecutorEnd because EXPLAIN ANALYZE needs to
+ *		include these actions in the total runtime.
+ *
+ *		We provide a function hook variable that lets loadable plugins
+ *		get control when ExecutorFinish is called.  Such a plugin would
+ *		normally call standard_ExecutorFinish().
+ *
+ * ----------------------------------------------------------------
+ */
+void
+ExecutorFinish(QueryDesc *queryDesc)
+{
+	if (ExecutorFinish_hook)
+		(*ExecutorFinish_hook) (queryDesc);
+	else
+		standard_ExecutorFinish(queryDesc);
+}
+
+void
+standard_ExecutorFinish(QueryDesc *queryDesc)
+{
+	EState	   *estate;
+	MemoryContext oldcontext;
+
+	/* sanity checks */
+	Assert(queryDesc != NULL);
+
+	estate = queryDesc->estate;
+
+	Assert(estate != NULL);
+	Assert(!(estate->es_top_eflags & EXEC_FLAG_EXPLAIN_ONLY));
+
+	/* This should be run once and only once per Executor instance */
+	Assert(!estate->es_finished);
+
+	/* Switch into per-query memory context */
+	oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
+
+	/* Allow instrumentation of Executor overall runtime */
+	if (queryDesc->totaltime)
+		InstrStartNode(queryDesc->totaltime);
+
+	/* Run ModifyTable nodes to completion */
+	ExecPostprocessPlan(estate);
+
+	/* Execute queued AFTER triggers, unless told not to */
+	if (!(estate->es_top_eflags & EXEC_FLAG_SKIP_TRIGGERS))
+		AfterTriggerEndQuery(estate);
+
+	if (queryDesc->totaltime)
+		InstrStopNode(queryDesc->totaltime, 0);
+
+	MemoryContextSwitchTo(oldcontext);
+
+	estate->es_finished = true;
+}
+
+/* ----------------------------------------------------------------
+ *		ExecutorEnd
+ *
+ *		This routine must be called at the end of execution of any
+ *		query plan
+ *
+ *		We provide a function hook variable that lets loadable plugins
+ *		get control when ExecutorEnd is called.  Such a plugin would
+ *		normally call standard_ExecutorEnd().
+ *
+ * ----------------------------------------------------------------
+ */
+void
+ExecutorEnd(QueryDesc *queryDesc)
+{
+	if (ExecutorEnd_hook)
+		(*ExecutorEnd_hook) (queryDesc);
+	else
+		standard_ExecutorEnd(queryDesc);
+}
+
+void
+standard_ExecutorEnd(QueryDesc *queryDesc)
+{
+	EState	   *estate;
+	MemoryContext oldcontext;
+
+	/* sanity checks */
+	Assert(queryDesc != NULL);
+
+	estate = queryDesc->estate;
+
+	Assert(estate != NULL);
+
+	/*
+	 * Check that ExecutorFinish was called, unless in EXPLAIN-only mode. This
+	 * Assert is needed because ExecutorFinish is new as of 9.1, and callers
+	 * might forget to call it.
+	 */
+	Assert(estate->es_finished ||
+		   (estate->es_top_eflags & EXEC_FLAG_EXPLAIN_ONLY));
+
+	/*
+	 * Switch into per-query memory context to run ExecEndPlan
+	 */
+	oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
+
+	ExecEndPlan(queryDesc->planstate, estate);
+
+	/* do away with our snapshots */
+	UnregisterSnapshot(estate->es_snapshot);
+	UnregisterSnapshot(estate->es_crosscheck_snapshot);
+
+	/*
+	 * Must switch out of context before destroying it
+	 */
+	MemoryContextSwitchTo(oldcontext);
+
+	/*
+	 * Release EState and per-query memory context.  This should release
+	 * everything the executor has allocated.
+	 */
+	FreeExecutorState(estate);
+
+	/* Reset queryDesc fields that no longer point to anything */
+	queryDesc->tupDesc = NULL;
+	queryDesc->estate = NULL;
+	queryDesc->planstate = NULL;
+	queryDesc->totaltime = NULL;
+}
+
+/* ----------------------------------------------------------------
+ *		ExecutorRewind
+ *
+ *		This routine may be called on an open queryDesc to rewind it
+ *		to the start.
+ * ----------------------------------------------------------------
+ */
+void
+ExecutorRewind(QueryDesc *queryDesc)
+{
+	EState	   *estate;
+	MemoryContext oldcontext;
+
+	/* sanity checks */
+	Assert(queryDesc != NULL);
+
+	estate = queryDesc->estate;
+
+	Assert(estate != NULL);
+
+	/* It's probably not sensible to rescan updating queries */
+	Assert(queryDesc->operation == CMD_SELECT);
+
+	/*
+	 * Switch into per-query memory context
+	 */
+	oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
+
+	/*
+	 * rescan plan
+	 */
+	ExecReScan(queryDesc->planstate);
+
+	MemoryContextSwitchTo(oldcontext);
+}
+
+
+/*
+ * ExecCheckRTPerms
+ *		Check access permissions for all relations listed in a range table.
+ *
+ * Returns true if permissions are adequate.  Otherwise, throws an appropriate
+ * error if ereport_on_violation is true, or simply returns false otherwise.
+ *
+ * Note that this does NOT address row-level security policies (aka: RLS).  If
+ * rows will be returned to the user as a result of this permission check
+ * passing, then RLS also needs to be consulted (and check_enable_rls()).
+ *
+ * See rewrite/rowsecurity.c.
+ */
+bool
+ExecCheckRTPerms(List *rangeTable, bool ereport_on_violation)
+{
+	ListCell   *l;
+	bool		result = true;
+
+	foreach(l, rangeTable)
+	{
+		RangeTblEntry *rte = (RangeTblEntry *) lfirst(l);
+
+		result = ExecCheckRTEPerms(rte);
+		if (!result)
+		{
+			Assert(rte->rtekind == RTE_RELATION);
+			if (ereport_on_violation)
+				aclcheck_error(ACLCHECK_NO_PRIV, get_relkind_objtype(get_rel_relkind(rte->relid)),
+							   get_rel_name(rte->relid));
+			return false;
+		}
+	}
+
+	if (ExecutorCheckPerms_hook)
+		result = (*ExecutorCheckPerms_hook) (rangeTable,
+											 ereport_on_violation);
+	return result;
+}
+
+/*
+ * ExecCheckRTEPerms
+ *		Check access permissions for a single RTE.
+ */
+static bool
+ExecCheckRTEPerms(RangeTblEntry *rte)
+{
+	AclMode		requiredPerms;
+	AclMode		relPerms;
+	AclMode		remainingPerms;
+	Oid			relOid;
+	Oid			userid;
+
+	/*
+	 * Only plain-relation RTEs need to be checked here.  Function RTEs are
+	 * checked when the function is prepared for execution.  Join, subquery,
+	 * and special RTEs need no checks.
+	 */
+	if (rte->rtekind != RTE_RELATION)
+		return true;
+
+	/*
+	 * No work if requiredPerms is empty.
+	 */
+	requiredPerms = rte->requiredPerms;
+	if (requiredPerms == 0)
+		return true;
+
+	relOid = rte->relid;
+
+	/*
+	 * userid to check as: current user unless we have a setuid indication.
+	 *
+	 * Note: GetUserId() is presently fast enough that there's no harm in
+	 * calling it separately for each RTE.  If that stops being true, we could
+	 * call it once in ExecCheckRTPerms and pass the userid down from there.
+	 * But for now, no need for the extra clutter.
+	 */
+	userid = rte->checkAsUser ? rte->checkAsUser : GetUserId();
+
+	/*
+	 * We must have *all* the requiredPerms bits, but some of the bits can be
+	 * satisfied from column-level rather than relation-level permissions.
+	 * First, remove any bits that are satisfied by relation permissions.
+	 */
+	relPerms = pg_class_aclmask(relOid, userid, requiredPerms, ACLMASK_ALL);
+	remainingPerms = requiredPerms & ~relPerms;
+	if (remainingPerms != 0)
+	{
+		int			col = -1;
+
+		/*
+		 * If we lack any permissions that exist only as relation permissions,
+		 * we can fail straight away.
+		 */
+		if (remainingPerms & ~(ACL_SELECT | ACL_INSERT | ACL_UPDATE))
+			return false;
+
+		/*
+		 * Check to see if we have the needed privileges at column level.
+		 *
+		 * Note: failures just report a table-level error; it would be nicer
+		 * to report a column-level error if we have some but not all of the
+		 * column privileges.
+		 */
+		if (remainingPerms & ACL_SELECT)
+		{
+			/*
+			 * When the query doesn't explicitly reference any columns (for
+			 * example, SELECT COUNT(*) FROM table), allow the query if we
+			 * have SELECT on any column of the rel, as per SQL spec.
+			 */
+			if (bms_is_empty(rte->selectedCols))
+			{
+				if (pg_attribute_aclcheck_all(relOid, userid, ACL_SELECT,
+											  ACLMASK_ANY) != ACLCHECK_OK)
+					return false;
+			}
+
+			while ((col = bms_next_member(rte->selectedCols, col)) >= 0)
+			{
+				/* bit #s are offset by FirstLowInvalidHeapAttributeNumber */
+				AttrNumber	attno = col + FirstLowInvalidHeapAttributeNumber;
+
+				if (attno == InvalidAttrNumber)
+				{
+					/* Whole-row reference, must have priv on all cols */
+					if (pg_attribute_aclcheck_all(relOid, userid, ACL_SELECT,
+												  ACLMASK_ALL) != ACLCHECK_OK)
+						return false;
+				}
+				else
+				{
+					if (pg_attribute_aclcheck(relOid, attno, userid,
+											  ACL_SELECT) != ACLCHECK_OK)
+						return false;
+				}
+			}
+		}
+
+		/*
+		 * Basically the same for the mod columns, for both INSERT and UPDATE
+		 * privilege as specified by remainingPerms.
+		 */
+		if (remainingPerms & ACL_INSERT && !ExecCheckRTEPermsModified(relOid,
+																	  userid,
+																	  rte->insertedCols,
+																	  ACL_INSERT))
+			return false;
+
+		if (remainingPerms & ACL_UPDATE && !ExecCheckRTEPermsModified(relOid,
+																	  userid,
+																	  rte->updatedCols,
+																	  ACL_UPDATE))
+			return false;
+	}
+	return true;
+}
+
+/*
+ * ExecCheckRTEPermsModified
+ *		Check INSERT or UPDATE access permissions for a single RTE (these
+ *		are processed uniformly).
+ */
+static bool
+ExecCheckRTEPermsModified(Oid relOid, Oid userid, Bitmapset *modifiedCols,
+						  AclMode requiredPerms)
+{
+	int			col = -1;
+
+	/*
+	 * When the query doesn't explicitly update any columns, allow the query
+	 * if we have permission on any column of the rel.  This is to handle
+	 * SELECT FOR UPDATE as well as possible corner cases in UPDATE.
+	 */
+	if (bms_is_empty(modifiedCols))
+	{
+		if (pg_attribute_aclcheck_all(relOid, userid, requiredPerms,
+									  ACLMASK_ANY) != ACLCHECK_OK)
+			return false;
+	}
+
+	while ((col = bms_next_member(modifiedCols, col)) >= 0)
+	{
+		/* bit #s are offset by FirstLowInvalidHeapAttributeNumber */
+		AttrNumber	attno = col + FirstLowInvalidHeapAttributeNumber;
+
+		if (attno == InvalidAttrNumber)
+		{
+			/* whole-row reference can't happen here */
+			elog(ERROR, "whole-row update is not implemented");
+		}
+		else
+		{
+			if (pg_attribute_aclcheck(relOid, attno, userid,
+									  requiredPerms) != ACLCHECK_OK)
+				return false;
+		}
+	}
+	return true;
+}
+
+/*
+ * Check that the query does not imply any writes to non-temp tables;
+ * unless we're in parallel mode, in which case don't even allow writes
+ * to temp tables.
+ *
+ * Note: in a Hot Standby this would need to reject writes to temp
+ * tables just as we do in parallel mode; but an HS standby can't have created
+ * any temp tables in the first place, so no need to check that.
+ */
+static void
+ExecCheckXactReadOnly(PlannedStmt *plannedstmt)
+{
+	ListCell   *l;
+
+	/*
+	 * Fail if write permissions are requested in parallel mode for table
+	 * (temp or non-temp), otherwise fail for any non-temp table.
+	 */
+	foreach(l, plannedstmt->rtable)
+	{
+		RangeTblEntry *rte = (RangeTblEntry *) lfirst(l);
+
+		if (rte->rtekind != RTE_RELATION)
+			continue;
+
+		if ((rte->requiredPerms & (~ACL_SELECT)) == 0)
+			continue;
+
+		if (isTempNamespace(get_rel_namespace(rte->relid)))
+			continue;
+
+		PreventCommandIfReadOnly(CreateCommandName((Node *) plannedstmt));
+	}
+
+	if (plannedstmt->commandType != CMD_SELECT || plannedstmt->hasModifyingCTE)
+		PreventCommandIfParallelMode(CreateCommandName((Node *) plannedstmt));
+}
+
+
+/* ----------------------------------------------------------------
+ *		InitPlan
+ *
+ *		Initializes the query plan: open files, allocate storage
+ *		and start up the rule manager
+ * ----------------------------------------------------------------
+ */
+static void
+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
+	 */
+	ExecCheckRTPerms(rangeTable, true);
+
+	/*
+	 * initialize the node's execution state
+	 */
+	ExecInitRangeTable(estate, rangeTable);
+
+	estate->es_plannedstmt = plannedstmt;
+
+	/*
+	 * Next, build the ExecRowMark array from the PlanRowMark(s), if any.
+	 */
+	if (plannedstmt->rowMarks)
+	{
+		estate->es_rowmarks = (ExecRowMark **)
+			palloc0(estate->es_range_table_size * sizeof(ExecRowMark *));
+		foreach(l, plannedstmt->rowMarks)
+		{
+			PlanRowMark *rc = (PlanRowMark *) lfirst(l);
+			Oid			relid;
+			Relation	relation;
+			ExecRowMark *erm;
+
+			/* ignore "parent" rowmarks; they are irrelevant at runtime */
+			if (rc->isParent)
+				continue;
+
+			/* get relation's OID (will produce InvalidOid if subquery) */
+			relid = exec_rt_fetch(rc->rti, estate)->relid;
+
+			/* open relation, if we need to access it for this mark type */
+			switch (rc->markType)
+			{
+				case ROW_MARK_EXCLUSIVE:
+				case ROW_MARK_NOKEYEXCLUSIVE:
+				case ROW_MARK_SHARE:
+				case ROW_MARK_KEYSHARE:
+				case ROW_MARK_REFERENCE:
+					relation = ExecGetRangeTableRelation(estate, rc->rti);
+					break;
+				case ROW_MARK_COPY:
+					/* no physical table access is required */
+					relation = NULL;
+					break;
+				default:
+					elog(ERROR, "unrecognized markType: %d", rc->markType);
+					relation = NULL;	/* keep compiler quiet */
+					break;
+			}
+
+			/* Check that relation is a legal target for marking */
+			if (relation)
+				CheckValidRowMarkRel(relation, rc->markType);
+
+			erm = (ExecRowMark *) palloc(sizeof(ExecRowMark));
+			erm->relation = relation;
+			erm->relid = relid;
+			erm->rti = rc->rti;
+			erm->prti = rc->prti;
+			erm->rowmarkId = rc->rowmarkId;
+			erm->markType = rc->markType;
+			erm->strength = rc->strength;
+			erm->waitPolicy = rc->waitPolicy;
+			erm->ermActive = false;
+			ItemPointerSetInvalid(&(erm->curCtid));
+			erm->ermExtra = NULL;
+
+			Assert(erm->rti > 0 && erm->rti <= estate->es_range_table_size &&
+				   estate->es_rowmarks[erm->rti - 1] == NULL);
+
+			estate->es_rowmarks[erm->rti - 1] = erm;
+		}
+	}
+
+	/*
+	 * Initialize the executor's tuple table to empty.
+	 */
+	estate->es_tupleTable = NIL;
+
+	/* signal that this EState is not used for EPQ */
+	estate->es_epq_active = NULL;
+
+	/*
+	 * Initialize private state information for each SubPlan.  We must do this
+	 * before running ExecInitNode on the main query tree, since
+	 * ExecInitSubPlan expects to be able to find these entries.
+	 */
+	Assert(estate->es_subplanstates == NIL);
+	i = 1;						/* subplan indices count from 1 */
+	foreach(l, plannedstmt->subplans)
+	{
+		Plan	   *subplan = (Plan *) lfirst(l);
+		PlanState  *subplanstate;
+		int			sp_eflags;
+
+		/*
+		 * A subplan will never need to do BACKWARD scan nor MARK/RESTORE. If
+		 * it is a parameterless subplan (not initplan), we suggest that it be
+		 * prepared to handle REWIND efficiently; otherwise there is no need.
+		 */
+		sp_eflags = eflags
+			& (EXEC_FLAG_EXPLAIN_ONLY | EXEC_FLAG_WITH_NO_DATA);
+		if (bms_is_member(i, plannedstmt->rewindPlanIDs))
+			sp_eflags |= EXEC_FLAG_REWIND;
+
+		subplanstate = ExecInitNode(subplan, estate, sp_eflags);
+
+		estate->es_subplanstates = lappend(estate->es_subplanstates,
+										   subplanstate);
+
+		i++;
+	}
+
+	/*
+	 * Initialize the private state information for all the nodes in the query
+	 * tree.  This opens files, allocates storage and leaves us ready to start
+	 * processing tuples.
+	 */
+	planstate = ExecInitNode(plan, estate, eflags);
+
+	/*
+	 * Get the tuple descriptor describing the type of tuples to return.
+	 */
+	tupType = ExecGetResultType(planstate);
+
+	/*
+	 * Initialize the junk filter if needed.  SELECT queries need a filter if
+	 * there are any junk attrs in the top-level tlist.
+	 */
+	if (operation == CMD_SELECT)
+	{
+		bool		junk_filter_needed = false;
+		ListCell   *tlist;
+
+		foreach(tlist, plan->targetlist)
+		{
+			TargetEntry *tle = (TargetEntry *) lfirst(tlist);
+
+			if (tle->resjunk)
+			{
+				junk_filter_needed = true;
+				break;
+			}
+		}
+
+		if (junk_filter_needed)
+		{
+			JunkFilter *j;
+			TupleTableSlot *slot;
+
+			slot = ExecInitExtraTupleSlot(estate, NULL, &TTSOpsVirtual);
+			j = ExecInitJunkFilter(planstate->plan->targetlist,
+								   slot);
+			estate->es_junkFilter = j;
+
+			/* Want to return the cleaned tuple type */
+			tupType = j->jf_cleanTupType;
+		}
+	}
+
+	queryDesc->tupDesc = tupType;
+	queryDesc->planstate = planstate;
+}
+
+/*
+ * Check that a proposed result relation is a legal target for the operation
+ *
+ * Generally the parser and/or planner should have noticed any such mistake
+ * already, but let's make sure.
+ *
+ * Note: when changing this function, you probably also need to look at
+ * CheckValidRowMarkRel.
+ */
+void
+CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation)
+{
+	Relation	resultRel = resultRelInfo->ri_RelationDesc;
+	TriggerDesc *trigDesc = resultRel->trigdesc;
+	FdwRoutine *fdwroutine;
+
+	switch (resultRel->rd_rel->relkind)
+	{
+		case RELKIND_RELATION:
+		case RELKIND_PARTITIONED_TABLE:
+			CheckCmdReplicaIdentity(resultRel, operation);
+			break;
+		case RELKIND_SEQUENCE:
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot change sequence \"%s\"",
+							RelationGetRelationName(resultRel))));
+			break;
+		case RELKIND_TOASTVALUE:
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot change TOAST relation \"%s\"",
+							RelationGetRelationName(resultRel))));
+			break;
+		case RELKIND_VIEW:
+
+			/*
+			 * Okay only if there's a suitable INSTEAD OF trigger.  Messages
+			 * here should match rewriteHandler.c's rewriteTargetView and
+			 * RewriteQuery, except that we omit errdetail because we haven't
+			 * got the information handy (and given that we really shouldn't
+			 * get here anyway, it's not worth great exertion to get).
+			 */
+			switch (operation)
+			{
+				case CMD_INSERT:
+					if (!trigDesc || !trigDesc->trig_insert_instead_row)
+						ereport(ERROR,
+								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+								 errmsg("cannot insert into view \"%s\"",
+										RelationGetRelationName(resultRel)),
+								 errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule.")));
+					break;
+				case CMD_UPDATE:
+					if (!trigDesc || !trigDesc->trig_update_instead_row)
+						ereport(ERROR,
+								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+								 errmsg("cannot update view \"%s\"",
+										RelationGetRelationName(resultRel)),
+								 errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule.")));
+					break;
+				case CMD_DELETE:
+					if (!trigDesc || !trigDesc->trig_delete_instead_row)
+						ereport(ERROR,
+								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+								 errmsg("cannot delete from view \"%s\"",
+										RelationGetRelationName(resultRel)),
+								 errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule.")));
+					break;
+				default:
+					elog(ERROR, "unrecognized CmdType: %d", (int) operation);
+					break;
+			}
+			break;
+		case RELKIND_MATVIEW:
+			if (!MatViewIncrementalMaintenanceIsEnabled())
+				ereport(ERROR,
+						(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+						 errmsg("cannot change materialized view \"%s\"",
+								RelationGetRelationName(resultRel))));
+			break;
+		case RELKIND_FOREIGN_TABLE:
+			/* Okay only if the FDW supports it */
+			fdwroutine = resultRelInfo->ri_FdwRoutine;
+			switch (operation)
+			{
+				case CMD_INSERT:
+					if (fdwroutine->ExecForeignInsert == NULL)
+						ereport(ERROR,
+								(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+								 errmsg("cannot insert into foreign table \"%s\"",
+										RelationGetRelationName(resultRel))));
+					if (fdwroutine->IsForeignRelUpdatable != NULL &&
+						(fdwroutine->IsForeignRelUpdatable(resultRel) & (1 << CMD_INSERT)) == 0)
+						ereport(ERROR,
+								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+								 errmsg("foreign table \"%s\" does not allow inserts",
+										RelationGetRelationName(resultRel))));
+					break;
+				case CMD_UPDATE:
+					if (fdwroutine->ExecForeignUpdate == NULL)
+						ereport(ERROR,
+								(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+								 errmsg("cannot update foreign table \"%s\"",
+										RelationGetRelationName(resultRel))));
+					if (fdwroutine->IsForeignRelUpdatable != NULL &&
+						(fdwroutine->IsForeignRelUpdatable(resultRel) & (1 << CMD_UPDATE)) == 0)
+						ereport(ERROR,
+								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+								 errmsg("foreign table \"%s\" does not allow updates",
+										RelationGetRelationName(resultRel))));
+					break;
+				case CMD_DELETE:
+					if (fdwroutine->ExecForeignDelete == NULL)
+						ereport(ERROR,
+								(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+								 errmsg("cannot delete from foreign table \"%s\"",
+										RelationGetRelationName(resultRel))));
+					if (fdwroutine->IsForeignRelUpdatable != NULL &&
+						(fdwroutine->IsForeignRelUpdatable(resultRel) & (1 << CMD_DELETE)) == 0)
+						ereport(ERROR,
+								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+								 errmsg("foreign table \"%s\" does not allow deletes",
+										RelationGetRelationName(resultRel))));
+					break;
+				default:
+					elog(ERROR, "unrecognized CmdType: %d", (int) operation);
+					break;
+			}
+			break;
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot change relation \"%s\"",
+							RelationGetRelationName(resultRel))));
+			break;
+	}
+}
+
+/*
+ * Check that a proposed rowmark target relation is a legal target
+ *
+ * In most cases parser and/or planner should have noticed this already, but
+ * they don't cover all cases.
+ */
+static void
+CheckValidRowMarkRel(Relation rel, RowMarkType markType)
+{
+	FdwRoutine *fdwroutine;
+
+	switch (rel->rd_rel->relkind)
+	{
+		case RELKIND_RELATION:
+		case RELKIND_PARTITIONED_TABLE:
+			/* OK */
+			break;
+		case RELKIND_SEQUENCE:
+			/* Must disallow this because we don't vacuum sequences */
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot lock rows in sequence \"%s\"",
+							RelationGetRelationName(rel))));
+			break;
+		case RELKIND_TOASTVALUE:
+			/* We could allow this, but there seems no good reason to */
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot lock rows in TOAST relation \"%s\"",
+							RelationGetRelationName(rel))));
+			break;
+		case RELKIND_VIEW:
+			/* Should not get here; planner should have expanded the view */
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot lock rows in view \"%s\"",
+							RelationGetRelationName(rel))));
+			break;
+		case RELKIND_MATVIEW:
+			/* Allow referencing a matview, but not actual locking clauses */
+			if (markType != ROW_MARK_REFERENCE)
+				ereport(ERROR,
+						(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+						 errmsg("cannot lock rows in materialized view \"%s\"",
+								RelationGetRelationName(rel))));
+			break;
+		case RELKIND_FOREIGN_TABLE:
+			/* Okay only if the FDW supports it */
+			fdwroutine = GetFdwRoutineForRelation(rel, false);
+			if (fdwroutine->RefetchForeignRow == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot lock rows in foreign table \"%s\"",
+								RelationGetRelationName(rel))));
+			break;
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+					 errmsg("cannot lock rows in relation \"%s\"",
+							RelationGetRelationName(rel))));
+			break;
+	}
+}
+
+/*
+ * Initialize ResultRelInfo data for one result relation
+ *
+ * Caution: before Postgres 9.1, this function included the relkind checking
+ * that's now in CheckValidResultRel, and it also did ExecOpenIndices if
+ * appropriate.  Be sure callers cover those needs.
+ */
+void
+InitResultRelInfo(ResultRelInfo *resultRelInfo,
+				  Relation resultRelationDesc,
+				  Index resultRelationIndex,
+				  ResultRelInfo *partition_root_rri,
+				  int instrument_options)
+{
+	MemSet(resultRelInfo, 0, sizeof(ResultRelInfo));
+	resultRelInfo->type = T_ResultRelInfo;
+	resultRelInfo->ri_RangeTableIndex = resultRelationIndex;
+	resultRelInfo->ri_RelationDesc = resultRelationDesc;
+	resultRelInfo->ri_NumIndices = 0;
+	resultRelInfo->ri_IndexRelationDescs = NULL;
+	resultRelInfo->ri_IndexRelationInfo = NULL;
+	/* make a copy so as not to depend on relcache info not changing... */
+	resultRelInfo->ri_TrigDesc = CopyTriggerDesc(resultRelationDesc->trigdesc);
+	if (resultRelInfo->ri_TrigDesc)
+	{
+		int			n = resultRelInfo->ri_TrigDesc->numtriggers;
+
+		resultRelInfo->ri_TrigFunctions = (FmgrInfo *)
+			palloc0(n * sizeof(FmgrInfo));
+		resultRelInfo->ri_TrigWhenExprs = (ExprState **)
+			palloc0(n * sizeof(ExprState *));
+		if (instrument_options)
+			resultRelInfo->ri_TrigInstrument = InstrAlloc(n, instrument_options, false);
+	}
+	else
+	{
+		resultRelInfo->ri_TrigFunctions = NULL;
+		resultRelInfo->ri_TrigWhenExprs = NULL;
+		resultRelInfo->ri_TrigInstrument = NULL;
+	}
+	if (resultRelationDesc->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+		resultRelInfo->ri_FdwRoutine = GetFdwRoutineForRelation(resultRelationDesc, true);
+	else
+		resultRelInfo->ri_FdwRoutine = NULL;
+
+	/* The following fields are set later if needed */
+	resultRelInfo->ri_RowIdAttNo = 0;
+	resultRelInfo->ri_projectNew = NULL;
+	resultRelInfo->ri_newTupleSlot = NULL;
+	resultRelInfo->ri_oldTupleSlot = NULL;
+	resultRelInfo->ri_projectNewInfoValid = false;
+	resultRelInfo->ri_FdwState = NULL;
+	resultRelInfo->ri_usesFdwDirectModify = false;
+	resultRelInfo->ri_ConstraintExprs = NULL;
+	resultRelInfo->ri_GeneratedExprs = NULL;
+	resultRelInfo->ri_projectReturning = NULL;
+	resultRelInfo->ri_onConflictArbiterIndexes = NIL;
+	resultRelInfo->ri_onConflict = NULL;
+	resultRelInfo->ri_ReturningSlot = NULL;
+	resultRelInfo->ri_TrigOldSlot = NULL;
+	resultRelInfo->ri_TrigNewSlot = NULL;
+
+	/*
+	 * Only ExecInitPartitionInfo() and ExecInitPartitionDispatchInfo() pass
+	 * non-NULL partition_root_rri.  For child relations that are part of the
+	 * initial query rather than being dynamically added by tuple routing,
+	 * this field is filled in ExecInitModifyTable().
+	 */
+	resultRelInfo->ri_RootResultRelInfo = partition_root_rri;
+	resultRelInfo->ri_RootToPartitionMap = NULL;	/* set by
+													 * ExecInitRoutingInfo */
+	resultRelInfo->ri_PartitionTupleSlot = NULL;	/* ditto */
+	resultRelInfo->ri_ChildToRootMap = NULL;
+	resultRelInfo->ri_ChildToRootMapValid = false;
+	resultRelInfo->ri_CopyMultiInsertBuffer = NULL;
+}
+
+/*
+ * ExecGetTriggerResultRel
+ *		Get a ResultRelInfo for a trigger target relation.
+ *
+ * Most of the time, triggers are fired on one of the result relations of the
+ * query, and so we can just return a member of the es_result_relations array,
+ * or the es_tuple_routing_result_relations list (if any). (Note: in self-join
+ * situations there might be multiple members with the same OID; if so it
+ * doesn't matter which one we pick.)
+ *
+ * However, it is sometimes necessary to fire triggers on other relations;
+ * this happens mainly when an RI update trigger queues additional triggers
+ * on other relations, which will be processed in the context of the outer
+ * query.  For efficiency's sake, we want to have a ResultRelInfo for those
+ * triggers too; that can avoid repeated re-opening of the relation.  (It
+ * also provides a way for EXPLAIN ANALYZE to report the runtimes of such
+ * triggers.)  So we make additional ResultRelInfo's as needed, and save them
+ * in es_trig_target_relations.
+ */
+ResultRelInfo *
+ExecGetTriggerResultRel(EState *estate, Oid relid)
+{
+	ResultRelInfo *rInfo;
+	ListCell   *l;
+	Relation	rel;
+	MemoryContext oldcontext;
+
+	/* Search through the query result relations */
+	foreach(l, estate->es_opened_result_relations)
+	{
+		rInfo = lfirst(l);
+		if (RelationGetRelid(rInfo->ri_RelationDesc) == relid)
+			return rInfo;
+	}
+
+	/*
+	 * Search through the result relations that were created during tuple
+	 * routing, if any.
+	 */
+	foreach(l, estate->es_tuple_routing_result_relations)
+	{
+		rInfo = (ResultRelInfo *) lfirst(l);
+		if (RelationGetRelid(rInfo->ri_RelationDesc) == relid)
+			return rInfo;
+	}
+
+	/* Nope, but maybe we already made an extra ResultRelInfo for it */
+	foreach(l, estate->es_trig_target_relations)
+	{
+		rInfo = (ResultRelInfo *) lfirst(l);
+		if (RelationGetRelid(rInfo->ri_RelationDesc) == relid)
+			return rInfo;
+	}
+	/* Nope, so we need a new one */
+
+	/*
+	 * Open the target relation's relcache entry.  We assume that an
+	 * appropriate lock is still held by the backend from whenever the trigger
+	 * event got queued, so we need take no new lock here.  Also, we need not
+	 * recheck the relkind, so no need for CheckValidResultRel.
+	 */
+	rel = table_open(relid, NoLock);
+
+	/*
+	 * Make the new entry in the right context.
+	 */
+	oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
+	rInfo = makeNode(ResultRelInfo);
+	InitResultRelInfo(rInfo,
+					  rel,
+					  0,		/* dummy rangetable index */
+					  NULL,
+					  estate->es_instrument);
+	estate->es_trig_target_relations =
+		lappend(estate->es_trig_target_relations, rInfo);
+	MemoryContextSwitchTo(oldcontext);
+
+	/*
+	 * Currently, we don't need any index information in ResultRelInfos used
+	 * only for triggers, so no need to call ExecOpenIndices.
+	 */
+
+	return rInfo;
+}
+
+/* ----------------------------------------------------------------
+ *		ExecPostprocessPlan
+ *
+ *		Give plan nodes a final chance to execute before shutdown
+ * ----------------------------------------------------------------
+ */
+static void
+ExecPostprocessPlan(EState *estate)
+{
+	ListCell   *lc;
+
+	/*
+	 * Make sure nodes run forward.
+	 */
+	estate->es_direction = ForwardScanDirection;
+
+	/*
+	 * Run any secondary ModifyTable nodes to completion, in case the main
+	 * query did not fetch all rows from them.  (We do this to ensure that
+	 * such nodes have predictable results.)
+	 */
+	foreach(lc, estate->es_auxmodifytables)
+	{
+		PlanState  *ps = (PlanState *) lfirst(lc);
+
+		for (;;)
+		{
+			TupleTableSlot *slot;
+
+			/* Reset the per-output-tuple exprcontext each time */
+			ResetPerTupleExprContext(estate);
+
+			slot = ExecProcNode(ps);
+
+			if (TupIsNull(slot))
+				break;
+		}
+	}
+}
+
+/* ----------------------------------------------------------------
+ *		ExecEndPlan
+ *
+ *		Cleans up the query plan -- closes files and frees up storage
+ *
+ * NOTE: we are no longer very worried about freeing storage per se
+ * in this code; FreeExecutorState should be guaranteed to release all
+ * memory that needs to be released.  What we are worried about doing
+ * is closing relations and dropping buffer pins.  Thus, for example,
+ * tuple tables must be cleared or dropped to ensure pins are released.
+ * ----------------------------------------------------------------
+ */
+static void
+ExecEndPlan(PlanState *planstate, EState *estate)
+{
+	ListCell   *l;
+
+	/*
+	 * shut down the node-type-specific query processing
+	 */
+	ExecEndNode(planstate);
+
+	/*
+	 * for subplans too
+	 */
+	foreach(l, estate->es_subplanstates)
+	{
+		PlanState  *subplanstate = (PlanState *) lfirst(l);
+
+		ExecEndNode(subplanstate);
+	}
+
+	/*
+	 * destroy the executor's tuple table.  Actually we only care about
+	 * releasing buffer pins and tupdesc refcounts; there's no need to pfree
+	 * the TupleTableSlots, since the containing memory context is about to go
+	 * away anyway.
+	 */
+	ExecResetTupleTable(estate->es_tupleTable, false);
+
+	/*
+	 * Close any Relations that have been opened for range table entries or
+	 * result relations.
+	 */
+	ExecCloseResultRelations(estate);
+	ExecCloseRangeTableRelations(estate);
+}
+
+/*
+ * Close any relations that have been opened for ResultRelInfos.
+ */
+void
+ExecCloseResultRelations(EState *estate)
+{
+	ListCell   *l;
+
+	/*
+	 * close indexes of result relation(s) if any.  (Rels themselves are
+	 * closed in ExecCloseRangeTableRelations())
+	 */
+	foreach(l, estate->es_opened_result_relations)
+	{
+		ResultRelInfo *resultRelInfo = lfirst(l);
+
+		ExecCloseIndices(resultRelInfo);
+	}
+
+	/* Close any relations that have been opened by ExecGetTriggerResultRel(). */
+	foreach(l, estate->es_trig_target_relations)
+	{
+		ResultRelInfo *resultRelInfo = (ResultRelInfo *) lfirst(l);
+
+		/*
+		 * Assert this is a "dummy" ResultRelInfo, see above.  Otherwise we
+		 * might be issuing a duplicate close against a Relation opened by
+		 * ExecGetRangeTableRelation.
+		 */
+		Assert(resultRelInfo->ri_RangeTableIndex == 0);
+
+		/*
+		 * Since ExecGetTriggerResultRel doesn't call ExecOpenIndices for
+		 * these rels, we needn't call ExecCloseIndices either.
+		 */
+		Assert(resultRelInfo->ri_NumIndices == 0);
+
+		table_close(resultRelInfo->ri_RelationDesc, NoLock);
+	}
+}
+
+/*
+ * Close all relations opened by ExecGetRangeTableRelation().
+ *
+ * We do not release any locks we might hold on those rels.
+ */
+void
+ExecCloseRangeTableRelations(EState *estate)
+{
+	int			i;
+
+	for (i = 0; i < estate->es_range_table_size; i++)
+	{
+		if (estate->es_relations[i])
+			table_close(estate->es_relations[i], NoLock);
+	}
+}
+
+/* ----------------------------------------------------------------
+ *		ExecutePlan
+ *
+ *		Processes the query plan until we have retrieved 'numberTuples' tuples,
+ *		moving in the specified direction.
+ *
+ *		Runs to completion if numberTuples is 0
+ *
+ * Note: the ctid attribute is a 'junk' attribute that is removed before the
+ * user can see it
+ * ----------------------------------------------------------------
+ */
+static void
+ExecutePlan(EState *estate,
+			PlanState *planstate,
+			bool use_parallel_mode,
+			CmdType operation,
+			bool sendTuples,
+			uint64 numberTuples,
+			ScanDirection direction,
+			DestReceiver *dest,
+			bool execute_once)
+{
+	TupleTableSlot *slot;
+	uint64		current_tuple_count;
+
+	/*
+	 * initialize local variables
+	 */
+	current_tuple_count = 0;
+
+	/*
+	 * Set the direction.
+	 */
+	estate->es_direction = direction;
+
+	/*
+	 * If the plan might potentially be executed multiple times, we must force
+	 * it to run without parallelism, because we might exit early.
+	 */
+	if (!execute_once)
+		use_parallel_mode = false;
+
+	estate->es_use_parallel_mode = use_parallel_mode;
+	if (use_parallel_mode)
+		EnterParallelMode();
+
+	/*
+	 * Loop until we've processed the proper number of tuples from the plan.
+	 */
+	for (;;)
+	{
+		/* Reset the per-output-tuple exprcontext */
+		ResetPerTupleExprContext(estate);
+
+		/*
+		 * Execute the plan and obtain a tuple
+		 */
+		slot = ExecProcNode(planstate);
+
+		/*
+		 * if the tuple is null, then we assume there is nothing more to
+		 * process so we just end the loop...
+		 */
+		if (TupIsNull(slot))
+			break;
+
+		/*
+		 * If we have a junk filter, then project a new tuple with the junk
+		 * removed.
+		 *
+		 * Store this new "clean" tuple in the junkfilter's resultSlot.
+		 * (Formerly, we stored it back over the "dirty" tuple, which is WRONG
+		 * because that tuple slot has the wrong descriptor.)
+		 */
+		if (estate->es_junkFilter != NULL)
+			slot = ExecFilterJunk(estate->es_junkFilter, slot);
+
+		/*
+		 * If we are supposed to send the tuple somewhere, do so. (In
+		 * practice, this is probably always the case at this point.)
+		 */
+		if (sendTuples)
+		{
+			/*
+			 * If we are not able to send the tuple, we assume the destination
+			 * has closed and no more tuples can be sent. If that's the case,
+			 * end the loop.
+			 */
+			if (!dest->receiveSlot(slot, dest))
+				break;
+		}
+
+		/*
+		 * Count tuples processed, if this is a SELECT.  (For other operation
+		 * types, the ModifyTable plan node must count the appropriate
+		 * events.)
+		 */
+		if (operation == CMD_SELECT)
+			(estate->es_processed)++;
+
+		/*
+		 * check our tuple count.. if we've processed the proper number then
+		 * quit, else loop again and process more tuples.  Zero numberTuples
+		 * means no limit.
+		 */
+		current_tuple_count++;
+		if (numberTuples && numberTuples == current_tuple_count)
+			break;
+	}
+
+	/*
+	 * If we know we won't need to back up, we can release resources at this
+	 * point.
+	 */
+	if (!(estate->es_top_eflags & EXEC_FLAG_BACKWARD))
+		(void) ExecShutdownNode(planstate);
+
+	if (use_parallel_mode)
+		ExitParallelMode();
+}
+
+
+/*
+ * ExecRelCheck --- check that tuple meets constraints for result relation
+ *
+ * Returns NULL if OK, else name of failed check constraint
+ */
+static const char *
+ExecRelCheck(ResultRelInfo *resultRelInfo,
+			 TupleTableSlot *slot, EState *estate)
+{
+	Relation	rel = resultRelInfo->ri_RelationDesc;
+	int			ncheck = rel->rd_att->constr->num_check;
+	ConstrCheck *check = rel->rd_att->constr->check;
+	ExprContext *econtext;
+	MemoryContext oldContext;
+	int			i;
+
+	/*
+	 * CheckConstraintFetch let this pass with only a warning, but now we
+	 * should fail rather than possibly failing to enforce an important
+	 * constraint.
+	 */
+	if (ncheck != rel->rd_rel->relchecks)
+		elog(ERROR, "%d pg_constraint record(s) missing for relation \"%s\"",
+			 rel->rd_rel->relchecks - ncheck, RelationGetRelationName(rel));
+
+	/*
+	 * If first time through for this result relation, build expression
+	 * nodetrees for rel's constraint expressions.  Keep them in the per-query
+	 * memory context so they'll survive throughout the query.
+	 */
+	if (resultRelInfo->ri_ConstraintExprs == NULL)
+	{
+		oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
+		resultRelInfo->ri_ConstraintExprs =
+			(ExprState **) palloc(ncheck * sizeof(ExprState *));
+		for (i = 0; i < ncheck; i++)
+		{
+			Expr	   *checkconstr;
+
+			checkconstr = stringToNode(check[i].ccbin);
+			resultRelInfo->ri_ConstraintExprs[i] =
+				ExecPrepareExpr(checkconstr, estate);
+		}
+		MemoryContextSwitchTo(oldContext);
+	}
+
+	/*
+	 * We will use the EState's per-tuple context for evaluating constraint
+	 * expressions (creating it if it's not already there).
+	 */
+	econtext = GetPerTupleExprContext(estate);
+
+	/* Arrange for econtext's scan tuple to be the tuple under test */
+	econtext->ecxt_scantuple = slot;
+
+	/* And evaluate the constraints */
+	for (i = 0; i < ncheck; i++)
+	{
+		ExprState  *checkconstr = resultRelInfo->ri_ConstraintExprs[i];
+
+		/*
+		 * NOTE: SQL specifies that a NULL result from a constraint expression
+		 * is not to be treated as a failure.  Therefore, use ExecCheck not
+		 * ExecQual.
+		 */
+		if (!ExecCheck(checkconstr, econtext))
+			return check[i].ccname;
+	}
+
+	/* NULL result means no error */
+	return NULL;
+}
+
+/*
+ * ExecPartitionCheck --- check that tuple meets the partition constraint.
+ *
+ * Returns true if it meets the partition constraint.  If the constraint
+ * fails and we're asked to emit an error, do so and don't return; otherwise
+ * return false.
+ */
+bool
+ExecPartitionCheck(ResultRelInfo *resultRelInfo, TupleTableSlot *slot,
+				   EState *estate, bool emitError)
+{
+	ExprContext *econtext;
+	bool		success;
+
+	/*
+	 * If first time through, build expression state tree for the partition
+	 * check expression.  (In the corner case where the partition check
+	 * expression is empty, ie there's a default partition and nothing else,
+	 * we'll be fooled into executing this code each time through.  But it's
+	 * pretty darn cheap in that case, so we don't worry about it.)
+	 */
+	if (resultRelInfo->ri_PartitionCheckExpr == NULL)
+	{
+		/*
+		 * Ensure that the qual tree and prepared expression are in the
+		 * query-lifespan context.
+		 */
+		MemoryContext oldcxt = MemoryContextSwitchTo(estate->es_query_cxt);
+		List	   *qual = RelationGetPartitionQual(resultRelInfo->ri_RelationDesc);
+
+		resultRelInfo->ri_PartitionCheckExpr = ExecPrepareCheck(qual, estate);
+		MemoryContextSwitchTo(oldcxt);
+	}
+
+	/*
+	 * We will use the EState's per-tuple context for evaluating constraint
+	 * expressions (creating it if it's not already there).
+	 */
+	econtext = GetPerTupleExprContext(estate);
+
+	/* Arrange for econtext's scan tuple to be the tuple under test */
+	econtext->ecxt_scantuple = slot;
+
+	/*
+	 * As in case of the catalogued constraints, we treat a NULL result as
+	 * success here, not a failure.
+	 */
+	success = ExecCheck(resultRelInfo->ri_PartitionCheckExpr, econtext);
+
+	/* if asked to emit error, don't actually return on failure */
+	if (!success && emitError)
+		ExecPartitionCheckEmitError(resultRelInfo, slot, estate);
+
+	return success;
+}
+
+/*
+ * ExecPartitionCheckEmitError - Form and emit an error message after a failed
+ * partition constraint check.
+ */
+void
+ExecPartitionCheckEmitError(ResultRelInfo *resultRelInfo,
+							TupleTableSlot *slot,
+							EState *estate)
+{
+	Oid			root_relid;
+	TupleDesc	tupdesc;
+	char	   *val_desc;
+	Bitmapset  *modifiedCols;
+
+	/*
+	 * If the tuple has been routed, it's been converted to the partition's
+	 * rowtype, which might differ from the root table's.  We must convert it
+	 * back to the root table's rowtype so that val_desc in the error message
+	 * matches the input tuple.
+	 */
+	if (resultRelInfo->ri_RootResultRelInfo)
+	{
+		ResultRelInfo *rootrel = resultRelInfo->ri_RootResultRelInfo;
+		TupleDesc	old_tupdesc;
+		AttrMap    *map;
+
+		root_relid = RelationGetRelid(rootrel->ri_RelationDesc);
+		tupdesc = RelationGetDescr(rootrel->ri_RelationDesc);
+
+		old_tupdesc = RelationGetDescr(resultRelInfo->ri_RelationDesc);
+		/* a reverse map */
+		map = build_attrmap_by_name_if_req(old_tupdesc, tupdesc);
+
+		/*
+		 * Partition-specific slot's tupdesc can't be changed, so allocate a
+		 * new one.
+		 */
+		if (map != NULL)
+			slot = execute_attr_map_slot(map, slot,
+										 MakeTupleTableSlot(tupdesc, &TTSOpsVirtual));
+		modifiedCols = bms_union(ExecGetInsertedCols(rootrel, estate),
+								 ExecGetUpdatedCols(rootrel, estate));
+	}
+	else
+	{
+		root_relid = RelationGetRelid(resultRelInfo->ri_RelationDesc);
+		tupdesc = RelationGetDescr(resultRelInfo->ri_RelationDesc);
+		modifiedCols = bms_union(ExecGetInsertedCols(resultRelInfo, estate),
+								 ExecGetUpdatedCols(resultRelInfo, estate));
+	}
+
+	val_desc = ExecBuildSlotValueDescription(root_relid,
+											 slot,
+											 tupdesc,
+											 modifiedCols,
+											 64);
+	ereport(ERROR,
+			(errcode(ERRCODE_CHECK_VIOLATION),
+			 errmsg("new row for relation \"%s\" violates partition constraint",
+					RelationGetRelationName(resultRelInfo->ri_RelationDesc)),
+			 val_desc ? errdetail("Failing row contains %s.", val_desc) : 0,
+			 errtable(resultRelInfo->ri_RelationDesc)));
+}
+
+/*
+ * ExecConstraints - check constraints of the tuple in 'slot'
+ *
+ * This checks the traditional NOT NULL and check constraints.
+ *
+ * The partition constraint is *NOT* checked.
+ *
+ * Note: 'slot' contains the tuple to check the constraints of, which may
+ * have been converted from the original input tuple after tuple routing.
+ * 'resultRelInfo' is the final result relation, after tuple routing.
+ */
+void
+ExecConstraints(ResultRelInfo *resultRelInfo,
+				TupleTableSlot *slot, EState *estate)
+{
+	Relation	rel = resultRelInfo->ri_RelationDesc;
+	TupleDesc	tupdesc = RelationGetDescr(rel);
+	TupleConstr *constr = tupdesc->constr;
+	Bitmapset  *modifiedCols;
+
+	Assert(constr);				/* we should not be called otherwise */
+
+	if (constr->has_not_null)
+	{
+		int			natts = tupdesc->natts;
+		int			attrChk;
+
+		for (attrChk = 1; attrChk <= natts; attrChk++)
+		{
+			Form_pg_attribute att = TupleDescAttr(tupdesc, attrChk - 1);
+
+			if (att->attnotnull && slot_attisnull(slot, attrChk))
+			{
+				char	   *val_desc;
+				Relation	orig_rel = rel;
+				TupleDesc	orig_tupdesc = RelationGetDescr(rel);
+
+				/*
+				 * If the tuple has been routed, it's been converted to the
+				 * partition's rowtype, which might differ from the root
+				 * table's.  We must convert it back to the root table's
+				 * rowtype so that val_desc shown error message matches the
+				 * input tuple.
+				 */
+				if (resultRelInfo->ri_RootResultRelInfo)
+				{
+					ResultRelInfo *rootrel = resultRelInfo->ri_RootResultRelInfo;
+					AttrMap    *map;
+
+					tupdesc = RelationGetDescr(rootrel->ri_RelationDesc);
+					/* a reverse map */
+					map = build_attrmap_by_name_if_req(orig_tupdesc,
+													   tupdesc);
+
+					/*
+					 * Partition-specific slot's tupdesc can't be changed, so
+					 * allocate a new one.
+					 */
+					if (map != NULL)
+						slot = execute_attr_map_slot(map, slot,
+													 MakeTupleTableSlot(tupdesc, &TTSOpsVirtual));
+					modifiedCols = bms_union(ExecGetInsertedCols(rootrel, estate),
+											 ExecGetUpdatedCols(rootrel, estate));
+					rel = rootrel->ri_RelationDesc;
+				}
+				else
+					modifiedCols = bms_union(ExecGetInsertedCols(resultRelInfo, estate),
+											 ExecGetUpdatedCols(resultRelInfo, estate));
+				val_desc = ExecBuildSlotValueDescription(RelationGetRelid(rel),
+														 slot,
+														 tupdesc,
+														 modifiedCols,
+														 64);
+
+				ereport(ERROR,
+						(errcode(ERRCODE_NOT_NULL_VIOLATION),
+						 errmsg("null value in column \"%s\" of relation \"%s\" violates not-null constraint",
+								NameStr(att->attname),
+								RelationGetRelationName(orig_rel)),
+						 val_desc ? errdetail("Failing row contains %s.", val_desc) : 0,
+						 errtablecol(orig_rel, attrChk)));
+			}
+		}
+	}
+
+	if (rel->rd_rel->relchecks > 0)
+	{
+		const char *failed;
+
+		if ((failed = ExecRelCheck(resultRelInfo, slot, estate)) != NULL)
+		{
+			char	   *val_desc;
+			Relation	orig_rel = rel;
+
+			/* See the comment above. */
+			if (resultRelInfo->ri_RootResultRelInfo)
+			{
+				ResultRelInfo *rootrel = resultRelInfo->ri_RootResultRelInfo;
+				TupleDesc	old_tupdesc = RelationGetDescr(rel);
+				AttrMap    *map;
+
+				tupdesc = RelationGetDescr(rootrel->ri_RelationDesc);
+				/* a reverse map */
+				map = build_attrmap_by_name_if_req(old_tupdesc,
+												   tupdesc);
+
+				/*
+				 * Partition-specific slot's tupdesc can't be changed, so
+				 * allocate a new one.
+				 */
+				if (map != NULL)
+					slot = execute_attr_map_slot(map, slot,
+												 MakeTupleTableSlot(tupdesc, &TTSOpsVirtual));
+				modifiedCols = bms_union(ExecGetInsertedCols(rootrel, estate),
+										 ExecGetUpdatedCols(rootrel, estate));
+				rel = rootrel->ri_RelationDesc;
+			}
+			else
+				modifiedCols = bms_union(ExecGetInsertedCols(resultRelInfo, estate),
+										 ExecGetUpdatedCols(resultRelInfo, estate));
+			val_desc = ExecBuildSlotValueDescription(RelationGetRelid(rel),
+													 slot,
+													 tupdesc,
+													 modifiedCols,
+													 64);
+			ereport(ERROR,
+					(errcode(ERRCODE_CHECK_VIOLATION),
+					 errmsg("new row for relation \"%s\" violates check constraint \"%s\"",
+							RelationGetRelationName(orig_rel), failed),
+					 val_desc ? errdetail("Failing row contains %s.", val_desc) : 0,
+					 errtableconstraint(orig_rel, failed)));
+		}
+	}
+}
+
+/*
+ * ExecWithCheckOptions -- check that tuple satisfies any WITH CHECK OPTIONs
+ * of the specified kind.
+ *
+ * Note that this needs to be called multiple times to ensure that all kinds of
+ * WITH CHECK OPTIONs are handled (both those from views which have the WITH
+ * CHECK OPTION set and from row-level security policies).  See ExecInsert()
+ * and ExecUpdate().
+ */
+void
+ExecWithCheckOptions(WCOKind kind, ResultRelInfo *resultRelInfo,
+					 TupleTableSlot *slot, EState *estate)
+{
+	Relation	rel = resultRelInfo->ri_RelationDesc;
+	TupleDesc	tupdesc = RelationGetDescr(rel);
+	ExprContext *econtext;
+	ListCell   *l1,
+			   *l2;
+
+	/*
+	 * We will use the EState's per-tuple context for evaluating constraint
+	 * expressions (creating it if it's not already there).
+	 */
+	econtext = GetPerTupleExprContext(estate);
+
+	/* Arrange for econtext's scan tuple to be the tuple under test */
+	econtext->ecxt_scantuple = slot;
+
+	/* Check each of the constraints */
+	forboth(l1, resultRelInfo->ri_WithCheckOptions,
+			l2, resultRelInfo->ri_WithCheckOptionExprs)
+	{
+		WithCheckOption *wco = (WithCheckOption *) lfirst(l1);
+		ExprState  *wcoExpr = (ExprState *) lfirst(l2);
+
+		/*
+		 * Skip any WCOs which are not the kind we are looking for at this
+		 * time.
+		 */
+		if (wco->kind != kind)
+			continue;
+
+		/*
+		 * WITH CHECK OPTION checks are intended to ensure that the new tuple
+		 * is visible (in the case of a view) or that it passes the
+		 * 'with-check' policy (in the case of row security). If the qual
+		 * evaluates to NULL or FALSE, then the new tuple won't be included in
+		 * the view or doesn't pass the 'with-check' policy for the table.
+		 */
+		if (!ExecQual(wcoExpr, econtext))
+		{
+			char	   *val_desc;
+			Bitmapset  *modifiedCols;
+
+			switch (wco->kind)
+			{
+					/*
+					 * For WITH CHECK OPTIONs coming from views, we might be
+					 * able to provide the details on the row, depending on
+					 * the permissions on the relation (that is, if the user
+					 * could view it directly anyway).  For RLS violations, we
+					 * don't include the data since we don't know if the user
+					 * should be able to view the tuple as that depends on the
+					 * USING policy.
+					 */
+				case WCO_VIEW_CHECK:
+					/* See the comment in ExecConstraints(). */
+					if (resultRelInfo->ri_RootResultRelInfo)
+					{
+						ResultRelInfo *rootrel = resultRelInfo->ri_RootResultRelInfo;
+						TupleDesc	old_tupdesc = RelationGetDescr(rel);
+						AttrMap    *map;
+
+						tupdesc = RelationGetDescr(rootrel->ri_RelationDesc);
+						/* a reverse map */
+						map = build_attrmap_by_name_if_req(old_tupdesc,
+														   tupdesc);
+
+						/*
+						 * Partition-specific slot's tupdesc can't be changed,
+						 * so allocate a new one.
+						 */
+						if (map != NULL)
+							slot = execute_attr_map_slot(map, slot,
+														 MakeTupleTableSlot(tupdesc, &TTSOpsVirtual));
+
+						modifiedCols = bms_union(ExecGetInsertedCols(rootrel, estate),
+												 ExecGetUpdatedCols(rootrel, estate));
+						rel = rootrel->ri_RelationDesc;
+					}
+					else
+						modifiedCols = bms_union(ExecGetInsertedCols(resultRelInfo, estate),
+												 ExecGetUpdatedCols(resultRelInfo, estate));
+					val_desc = ExecBuildSlotValueDescription(RelationGetRelid(rel),
+															 slot,
+															 tupdesc,
+															 modifiedCols,
+															 64);
+
+					ereport(ERROR,
+							(errcode(ERRCODE_WITH_CHECK_OPTION_VIOLATION),
+							 errmsg("new row violates check option for view \"%s\"",
+									wco->relname),
+							 val_desc ? errdetail("Failing row contains %s.",
+												  val_desc) : 0));
+					break;
+				case WCO_RLS_INSERT_CHECK:
+				case WCO_RLS_UPDATE_CHECK:
+					if (wco->polname != NULL)
+						ereport(ERROR,
+								(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+								 errmsg("new row violates row-level security policy \"%s\" for table \"%s\"",
+										wco->polname, wco->relname)));
+					else
+						ereport(ERROR,
+								(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+								 errmsg("new row violates row-level security policy for table \"%s\"",
+										wco->relname)));
+					break;
+				case WCO_RLS_CONFLICT_CHECK:
+					if (wco->polname != NULL)
+						ereport(ERROR,
+								(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+								 errmsg("new row violates row-level security policy \"%s\" (USING expression) for table \"%s\"",
+										wco->polname, wco->relname)));
+					else
+						ereport(ERROR,
+								(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+								 errmsg("new row violates row-level security policy (USING expression) for table \"%s\"",
+										wco->relname)));
+					break;
+				default:
+					elog(ERROR, "unrecognized WCO kind: %u", wco->kind);
+					break;
+			}
+		}
+	}
+}
+
+/*
+ * ExecBuildSlotValueDescription -- construct a string representing a tuple
+ *
+ * This is intentionally very similar to BuildIndexValueDescription, but
+ * unlike that function, we truncate long field values (to at most maxfieldlen
+ * bytes).  That seems necessary here since heap field values could be very
+ * long, whereas index entries typically aren't so wide.
+ *
+ * Also, unlike the case with index entries, we need to be prepared to ignore
+ * dropped columns.  We used to use the slot's tuple descriptor to decode the
+ * data, but the slot's descriptor doesn't identify dropped columns, so we
+ * now need to be passed the relation's descriptor.
+ *
+ * Note that, like BuildIndexValueDescription, if the user does not have
+ * permission to view any of the columns involved, a NULL is returned.  Unlike
+ * BuildIndexValueDescription, if the user has access to view a subset of the
+ * column involved, that subset will be returned with a key identifying which
+ * columns they are.
+ */
+static char *
+ExecBuildSlotValueDescription(Oid reloid,
+							  TupleTableSlot *slot,
+							  TupleDesc tupdesc,
+							  Bitmapset *modifiedCols,
+							  int maxfieldlen)
+{
+	StringInfoData buf;
+	StringInfoData collist;
+	bool		write_comma = false;
+	bool		write_comma_collist = false;
+	int			i;
+	AclResult	aclresult;
+	bool		table_perm = false;
+	bool		any_perm = false;
+
+	/*
+	 * Check if RLS is enabled and should be active for the relation; if so,
+	 * then don't return anything.  Otherwise, go through normal permission
+	 * checks.
+	 */
+	if (check_enable_rls(reloid, InvalidOid, true) == RLS_ENABLED)
+		return NULL;
+
+	initStringInfo(&buf);
+
+	appendStringInfoChar(&buf, '(');
+
+	/*
+	 * Check if the user has permissions to see the row.  Table-level SELECT
+	 * allows access to all columns.  If the user does not have table-level
+	 * SELECT then we check each column and include those the user has SELECT
+	 * rights on.  Additionally, we always include columns the user provided
+	 * data for.
+	 */
+	aclresult = pg_class_aclcheck(reloid, GetUserId(), ACL_SELECT);
+	if (aclresult != ACLCHECK_OK)
+	{
+		/* Set up the buffer for the column list */
+		initStringInfo(&collist);
+		appendStringInfoChar(&collist, '(');
+	}
+	else
+		table_perm = any_perm = true;
+
+	/* Make sure the tuple is fully deconstructed */
+	slot_getallattrs(slot);
+
+	for (i = 0; i < tupdesc->natts; i++)
+	{
+		bool		column_perm = false;
+		char	   *val;
+		int			vallen;
+		Form_pg_attribute att = TupleDescAttr(tupdesc, i);
+
+		/* ignore dropped columns */
+		if (att->attisdropped)
+			continue;
+
+		if (!table_perm)
+		{
+			/*
+			 * No table-level SELECT, so need to make sure they either have
+			 * SELECT rights on the column or that they have provided the data
+			 * for the column.  If not, omit this column from the error
+			 * message.
+			 */
+			aclresult = pg_attribute_aclcheck(reloid, att->attnum,
+											  GetUserId(), ACL_SELECT);
+			if (bms_is_member(att->attnum - FirstLowInvalidHeapAttributeNumber,
+							  modifiedCols) || aclresult == ACLCHECK_OK)
+			{
+				column_perm = any_perm = true;
+
+				if (write_comma_collist)
+					appendStringInfoString(&collist, ", ");
+				else
+					write_comma_collist = true;
+
+				appendStringInfoString(&collist, NameStr(att->attname));
+			}
+		}
+
+		if (table_perm || column_perm)
+		{
+			if (slot->tts_isnull[i])
+				val = "null";
+			else
+			{
+				Oid			foutoid;
+				bool		typisvarlena;
+
+				getTypeOutputInfo(att->atttypid,
+								  &foutoid, &typisvarlena);
+				val = OidOutputFunctionCall(foutoid, slot->tts_values[i]);
+			}
+
+			if (write_comma)
+				appendStringInfoString(&buf, ", ");
+			else
+				write_comma = true;
+
+			/* truncate if needed */
+			vallen = strlen(val);
+			if (vallen <= maxfieldlen)
+				appendBinaryStringInfo(&buf, val, vallen);
+			else
+			{
+				vallen = pg_mbcliplen(val, vallen, maxfieldlen);
+				appendBinaryStringInfo(&buf, val, vallen);
+				appendStringInfoString(&buf, "...");
+			}
+		}
+	}
+
+	/* If we end up with zero columns being returned, then return NULL. */
+	if (!any_perm)
+		return NULL;
+
+	appendStringInfoChar(&buf, ')');
+
+	if (!table_perm)
+	{
+		appendStringInfoString(&collist, ") = ");
+		appendBinaryStringInfo(&collist, buf.data, buf.len);
+
+		return collist.data;
+	}
+
+	return buf.data;
+}
+
+
+/*
+ * ExecUpdateLockMode -- find the appropriate UPDATE tuple lock mode for a
+ * given ResultRelInfo
+ */
+LockTupleMode
+ExecUpdateLockMode(EState *estate, ResultRelInfo *relinfo)
+{
+	Bitmapset  *keyCols;
+	Bitmapset  *updatedCols;
+
+	/*
+	 * Compute lock mode to use.  If columns that are part of the key have not
+	 * been modified, then we can use a weaker lock, allowing for better
+	 * concurrency.
+	 */
+	updatedCols = ExecGetAllUpdatedCols(relinfo, estate);
+	keyCols = RelationGetIndexAttrBitmap(relinfo->ri_RelationDesc,
+										 INDEX_ATTR_BITMAP_KEY);
+
+	if (bms_overlap(keyCols, updatedCols))
+		return LockTupleExclusive;
+
+	return LockTupleNoKeyExclusive;
+}
+
+/*
+ * ExecFindRowMark -- find the ExecRowMark struct for given rangetable index
+ *
+ * If no such struct, either return NULL or throw error depending on missing_ok
+ */
+ExecRowMark *
+ExecFindRowMark(EState *estate, Index rti, bool missing_ok)
+{
+	if (rti > 0 && rti <= estate->es_range_table_size &&
+		estate->es_rowmarks != NULL)
+	{
+		ExecRowMark *erm = estate->es_rowmarks[rti - 1];
+
+		if (erm)
+			return erm;
+	}
+	if (!missing_ok)
+		elog(ERROR, "failed to find ExecRowMark for rangetable index %u", rti);
+	return NULL;
+}
+
+/*
+ * ExecBuildAuxRowMark -- create an ExecAuxRowMark struct
+ *
+ * Inputs are the underlying ExecRowMark struct and the targetlist of the
+ * input plan node (not planstate node!).  We need the latter to find out
+ * the column numbers of the resjunk columns.
+ */
+ExecAuxRowMark *
+ExecBuildAuxRowMark(ExecRowMark *erm, List *targetlist)
+{
+	ExecAuxRowMark *aerm = (ExecAuxRowMark *) palloc0(sizeof(ExecAuxRowMark));
+	char		resname[32];
+
+	aerm->rowmark = erm;
+
+	/* Look up the resjunk columns associated with this rowmark */
+	if (erm->markType != ROW_MARK_COPY)
+	{
+		/* need ctid for all methods other than COPY */
+		snprintf(resname, sizeof(resname), "ctid%u", erm->rowmarkId);
+		aerm->ctidAttNo = ExecFindJunkAttributeInTlist(targetlist,
+													   resname);
+		if (!AttributeNumberIsValid(aerm->ctidAttNo))
+			elog(ERROR, "could not find junk %s column", resname);
+	}
+	else
+	{
+		/* need wholerow if COPY */
+		snprintf(resname, sizeof(resname), "wholerow%u", erm->rowmarkId);
+		aerm->wholeAttNo = ExecFindJunkAttributeInTlist(targetlist,
+														resname);
+		if (!AttributeNumberIsValid(aerm->wholeAttNo))
+			elog(ERROR, "could not find junk %s column", resname);
+	}
+
+	/* if child rel, need tableoid */
+	if (erm->rti != erm->prti)
+	{
+		snprintf(resname, sizeof(resname), "tableoid%u", erm->rowmarkId);
+		aerm->toidAttNo = ExecFindJunkAttributeInTlist(targetlist,
+													   resname);
+		if (!AttributeNumberIsValid(aerm->toidAttNo))
+			elog(ERROR, "could not find junk %s column", resname);
+	}
+
+	return aerm;
+}
+
+
+/*
+ * EvalPlanQual logic --- recheck modified tuple(s) to see if we want to
+ * process the updated version under READ COMMITTED rules.
+ *
+ * See backend/executor/README for some info about how this works.
+ */
+
+
+/*
+ * Check the updated version of a tuple to see if we want to process it under
+ * READ COMMITTED rules.
+ *
+ *	epqstate - state for EvalPlanQual rechecking
+ *	relation - table containing tuple
+ *	rti - rangetable index of table containing tuple
+ *	inputslot - tuple for processing - this can be the slot from
+ *		EvalPlanQualSlot(), for the increased efficiency.
+ *
+ * This tests whether the tuple in inputslot still matches the relevant
+ * quals. For that result to be useful, typically the input tuple has to be
+ * last row version (otherwise the result isn't particularly useful) and
+ * locked (otherwise the result might be out of date). That's typically
+ * achieved by using table_tuple_lock() with the
+ * TUPLE_LOCK_FLAG_FIND_LAST_VERSION flag.
+ *
+ * Returns a slot containing the new candidate update/delete tuple, or
+ * NULL if we determine we shouldn't process the row.
+ */
+TupleTableSlot *
+EvalPlanQual(EPQState *epqstate, Relation relation,
+			 Index rti, TupleTableSlot *inputslot)
+{
+	TupleTableSlot *slot;
+	TupleTableSlot *testslot;
+
+	Assert(rti > 0);
+
+	/*
+	 * Need to run a recheck subquery.  Initialize or reinitialize EPQ state.
+	 */
+	EvalPlanQualBegin(epqstate);
+
+	/*
+	 * Callers will often use the EvalPlanQualSlot to store the tuple to avoid
+	 * an unnecessary copy.
+	 */
+	testslot = EvalPlanQualSlot(epqstate, relation, rti);
+	if (testslot != inputslot)
+		ExecCopySlot(testslot, inputslot);
+
+	/*
+	 * Run the EPQ query.  We assume it will return at most one tuple.
+	 */
+	slot = EvalPlanQualNext(epqstate);
+
+	/*
+	 * If we got a tuple, force the slot to materialize the tuple so that it
+	 * is not dependent on any local state in the EPQ query (in particular,
+	 * it's highly likely that the slot contains references to any pass-by-ref
+	 * datums that may be present in copyTuple).  As with the next step, this
+	 * is to guard against early re-use of the EPQ query.
+	 */
+	if (!TupIsNull(slot))
+		ExecMaterializeSlot(slot);
+
+	/*
+	 * Clear out the test tuple.  This is needed in case the EPQ query is
+	 * re-used to test a tuple for a different relation.  (Not clear that can
+	 * really happen, but let's be safe.)
+	 */
+	ExecClearTuple(testslot);
+
+	return slot;
+}
+
+/*
+ * EvalPlanQualInit -- initialize during creation of a plan state node
+ * that might need to invoke EPQ processing.
+ *
+ * Note: subplan/auxrowmarks can be NULL/NIL if they will be set later
+ * with EvalPlanQualSetPlan.
+ */
+void
+EvalPlanQualInit(EPQState *epqstate, EState *parentestate,
+				 Plan *subplan, List *auxrowmarks, int epqParam)
+{
+	Index		rtsize = parentestate->es_range_table_size;
+
+	/* initialize data not changing over EPQState's lifetime */
+	epqstate->parentestate = parentestate;
+	epqstate->epqParam = epqParam;
+
+	/*
+	 * Allocate space to reference a slot for each potential rti - do so now
+	 * rather than in EvalPlanQualBegin(), as done for other dynamically
+	 * allocated resources, so EvalPlanQualSlot() can be used to hold tuples
+	 * that *may* need EPQ later, without forcing the overhead of
+	 * EvalPlanQualBegin().
+	 */
+	epqstate->tuple_table = NIL;
+	epqstate->relsubs_slot = (TupleTableSlot **)
+		palloc0(rtsize * sizeof(TupleTableSlot *));
+
+	/* ... and remember data that EvalPlanQualBegin will need */
+	epqstate->plan = subplan;
+	epqstate->arowMarks = auxrowmarks;
+
+	/* ... and mark the EPQ state inactive */
+	epqstate->origslot = NULL;
+	epqstate->recheckestate = NULL;
+	epqstate->recheckplanstate = NULL;
+	epqstate->relsubs_rowmark = NULL;
+	epqstate->relsubs_done = NULL;
+}
+
+/*
+ * EvalPlanQualSetPlan -- set or change subplan of an EPQState.
+ *
+ * We used to need this so that ModifyTable could deal with multiple subplans.
+ * It could now be refactored out of existence.
+ */
+void
+EvalPlanQualSetPlan(EPQState *epqstate, Plan *subplan, List *auxrowmarks)
+{
+	/* If we have a live EPQ query, shut it down */
+	EvalPlanQualEnd(epqstate);
+	/* And set/change the plan pointer */
+	epqstate->plan = subplan;
+	/* The rowmarks depend on the plan, too */
+	epqstate->arowMarks = auxrowmarks;
+}
+
+/*
+ * Return, and create if necessary, a slot for an EPQ test tuple.
+ *
+ * Note this only requires EvalPlanQualInit() to have been called,
+ * EvalPlanQualBegin() is not necessary.
+ */
+TupleTableSlot *
+EvalPlanQualSlot(EPQState *epqstate,
+				 Relation relation, Index rti)
+{
+	TupleTableSlot **slot;
+
+	Assert(relation);
+	Assert(rti > 0 && rti <= epqstate->parentestate->es_range_table_size);
+	slot = &epqstate->relsubs_slot[rti - 1];
+
+	if (*slot == NULL)
+	{
+		MemoryContext oldcontext;
+
+		oldcontext = MemoryContextSwitchTo(epqstate->parentestate->es_query_cxt);
+		*slot = table_slot_create(relation, &epqstate->tuple_table);
+		MemoryContextSwitchTo(oldcontext);
+	}
+
+	return *slot;
+}
+
+/*
+ * Fetch the current row value for a non-locked relation, identified by rti,
+ * that needs to be scanned by an EvalPlanQual operation.  origslot must have
+ * been set to contain the current result row (top-level row) that we need to
+ * recheck.  Returns true if a substitution tuple was found, false if not.
+ */
+bool
+EvalPlanQualFetchRowMark(EPQState *epqstate, Index rti, TupleTableSlot *slot)
+{
+	ExecAuxRowMark *earm = epqstate->relsubs_rowmark[rti - 1];
+	ExecRowMark *erm = earm->rowmark;
+	Datum		datum;
+	bool		isNull;
+
+	Assert(earm != NULL);
+	Assert(epqstate->origslot != NULL);
+
+	if (RowMarkRequiresRowShareLock(erm->markType))
+		elog(ERROR, "EvalPlanQual doesn't support locking rowmarks");
+
+	/* if child rel, must check whether it produced this row */
+	if (erm->rti != erm->prti)
+	{
+		Oid			tableoid;
+
+		datum = ExecGetJunkAttribute(epqstate->origslot,
+									 earm->toidAttNo,
+									 &isNull);
+		/* non-locked rels could be on the inside of outer joins */
+		if (isNull)
+			return false;
+
+		tableoid = DatumGetObjectId(datum);
+
+		Assert(OidIsValid(erm->relid));
+		if (tableoid != erm->relid)
+		{
+			/* this child is inactive right now */
+			return false;
+		}
+	}
+
+	if (erm->markType == ROW_MARK_REFERENCE)
+	{
+		Assert(erm->relation != NULL);
+
+		/* fetch the tuple's ctid */
+		datum = ExecGetJunkAttribute(epqstate->origslot,
+									 earm->ctidAttNo,
+									 &isNull);
+		/* non-locked rels could be on the inside of outer joins */
+		if (isNull)
+			return false;
+
+		/* fetch requests on foreign tables must be passed to their FDW */
+		if (erm->relation->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+		{
+			FdwRoutine *fdwroutine;
+			bool		updated = false;
+
+			fdwroutine = GetFdwRoutineForRelation(erm->relation, false);
+			/* this should have been checked already, but let's be safe */
+			if (fdwroutine->RefetchForeignRow == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("cannot lock rows in foreign table \"%s\"",
+								RelationGetRelationName(erm->relation))));
+
+			fdwroutine->RefetchForeignRow(epqstate->recheckestate,
+										  erm,
+										  datum,
+										  slot,
+										  &updated);
+			if (TupIsNull(slot))
+				elog(ERROR, "failed to fetch tuple for EvalPlanQual recheck");
+
+			/*
+			 * Ideally we'd insist on updated == false here, but that assumes
+			 * that FDWs can track that exactly, which they might not be able
+			 * to.  So just ignore the flag.
+			 */
+			return true;
+		}
+		else
+		{
+			/* ordinary table, fetch the tuple */
+			if (!table_tuple_fetch_row_version(erm->relation,
+											   (ItemPointer) DatumGetPointer(datum),
+											   SnapshotAny, slot))
+				elog(ERROR, "failed to fetch tuple for EvalPlanQual recheck");
+			return true;
+		}
+	}
+	else
+	{
+		Assert(erm->markType == ROW_MARK_COPY);
+
+		/* fetch the whole-row Var for the relation */
+		datum = ExecGetJunkAttribute(epqstate->origslot,
+									 earm->wholeAttNo,
+									 &isNull);
+		/* non-locked rels could be on the inside of outer joins */
+		if (isNull)
+			return false;
+
+		ExecStoreHeapTupleDatum(datum, slot);
+		return true;
+	}
+}
+
+/*
+ * Fetch the next row (if any) from EvalPlanQual testing
+ *
+ * (In practice, there should never be more than one row...)
+ */
+TupleTableSlot *
+EvalPlanQualNext(EPQState *epqstate)
+{
+	MemoryContext oldcontext;
+	TupleTableSlot *slot;
+
+	oldcontext = MemoryContextSwitchTo(epqstate->recheckestate->es_query_cxt);
+	slot = ExecProcNode(epqstate->recheckplanstate);
+	MemoryContextSwitchTo(oldcontext);
+
+	return slot;
+}
+
+/*
+ * Initialize or reset an EvalPlanQual state tree
+ */
+void
+EvalPlanQualBegin(EPQState *epqstate)
+{
+	EState	   *parentestate = epqstate->parentestate;
+	EState	   *recheckestate = epqstate->recheckestate;
+
+	if (recheckestate == NULL)
+	{
+		/* First time through, so create a child EState */
+		EvalPlanQualStart(epqstate, epqstate->plan);
+	}
+	else
+	{
+		/*
+		 * We already have a suitable child EPQ tree, so just reset it.
+		 */
+		Index		rtsize = parentestate->es_range_table_size;
+		PlanState  *rcplanstate = epqstate->recheckplanstate;
+
+		MemSet(epqstate->relsubs_done, 0, rtsize * sizeof(bool));
+
+		/* Recopy current values of parent parameters */
+		if (parentestate->es_plannedstmt->paramExecTypes != NIL)
+		{
+			int			i;
+
+			/*
+			 * Force evaluation of any InitPlan outputs that could be needed
+			 * by the subplan, just in case they got reset since
+			 * EvalPlanQualStart (see comments therein).
+			 */
+			ExecSetParamPlanMulti(rcplanstate->plan->extParam,
+								  GetPerTupleExprContext(parentestate));
+
+			i = list_length(parentestate->es_plannedstmt->paramExecTypes);
+
+			while (--i >= 0)
+			{
+				/* copy value if any, but not execPlan link */
+				recheckestate->es_param_exec_vals[i].value =
+					parentestate->es_param_exec_vals[i].value;
+				recheckestate->es_param_exec_vals[i].isnull =
+					parentestate->es_param_exec_vals[i].isnull;
+			}
+		}
+
+		/*
+		 * Mark child plan tree as needing rescan at all scan nodes.  The
+		 * first ExecProcNode will take care of actually doing the rescan.
+		 */
+		rcplanstate->chgParam = bms_add_member(rcplanstate->chgParam,
+											   epqstate->epqParam);
+	}
+}
+
+/*
+ * Start execution of an EvalPlanQual plan tree.
+ *
+ * This is a cut-down version of ExecutorStart(): we copy some state from
+ * the top-level estate rather than initializing it fresh.
+ */
+static void
+EvalPlanQualStart(EPQState *epqstate, Plan *planTree)
+{
+	EState	   *parentestate = epqstate->parentestate;
+	Index		rtsize = parentestate->es_range_table_size;
+	EState	   *rcestate;
+	MemoryContext oldcontext;
+	ListCell   *l;
+
+	epqstate->recheckestate = rcestate = CreateExecutorState();
+
+	oldcontext = MemoryContextSwitchTo(rcestate->es_query_cxt);
+
+	/* signal that this is an EState for executing EPQ */
+	rcestate->es_epq_active = epqstate;
+
+	/*
+	 * Child EPQ EStates share the parent's copy of unchanging state such as
+	 * the snapshot, rangetable, and external Param info.  They need their own
+	 * copies of local state, including a tuple table, es_param_exec_vals,
+	 * result-rel info, etc.
+	 */
+	rcestate->es_direction = ForwardScanDirection;
+	rcestate->es_snapshot = parentestate->es_snapshot;
+	rcestate->es_crosscheck_snapshot = parentestate->es_crosscheck_snapshot;
+	rcestate->es_range_table = parentestate->es_range_table;
+	rcestate->es_range_table_size = parentestate->es_range_table_size;
+	rcestate->es_relations = parentestate->es_relations;
+	rcestate->es_queryEnv = parentestate->es_queryEnv;
+	rcestate->es_rowmarks = parentestate->es_rowmarks;
+	rcestate->es_plannedstmt = parentestate->es_plannedstmt;
+	rcestate->es_junkFilter = parentestate->es_junkFilter;
+	rcestate->es_output_cid = parentestate->es_output_cid;
+
+	/*
+	 * ResultRelInfos needed by subplans are initialized from scratch when the
+	 * subplans themselves are initialized.
+	 */
+	rcestate->es_result_relations = NULL;
+	/* es_trig_target_relations must NOT be copied */
+	rcestate->es_top_eflags = parentestate->es_top_eflags;
+	rcestate->es_instrument = parentestate->es_instrument;
+	/* es_auxmodifytables must NOT be copied */
+
+	/*
+	 * The external param list is simply shared from parent.  The internal
+	 * param workspace has to be local state, but we copy the initial values
+	 * from the parent, so as to have access to any param values that were
+	 * already set from other parts of the parent's plan tree.
+	 */
+	rcestate->es_param_list_info = parentestate->es_param_list_info;
+	if (parentestate->es_plannedstmt->paramExecTypes != NIL)
+	{
+		int			i;
+
+		/*
+		 * Force evaluation of any InitPlan outputs that could be needed by
+		 * the subplan.  (With more complexity, maybe we could postpone this
+		 * till the subplan actually demands them, but it doesn't seem worth
+		 * the trouble; this is a corner case already, since usually the
+		 * InitPlans would have been evaluated before reaching EvalPlanQual.)
+		 *
+		 * This will not touch output params of InitPlans that occur somewhere
+		 * within the subplan tree, only those that are attached to the
+		 * ModifyTable node or above it and are referenced within the subplan.
+		 * That's OK though, because the planner would only attach such
+		 * InitPlans to a lower-level SubqueryScan node, and EPQ execution
+		 * will not descend into a SubqueryScan.
+		 *
+		 * The EState's per-output-tuple econtext is sufficiently short-lived
+		 * for this, since it should get reset before there is any chance of
+		 * doing EvalPlanQual again.
+		 */
+		ExecSetParamPlanMulti(planTree->extParam,
+							  GetPerTupleExprContext(parentestate));
+
+		/* now make the internal param workspace ... */
+		i = list_length(parentestate->es_plannedstmt->paramExecTypes);
+		rcestate->es_param_exec_vals = (ParamExecData *)
+			palloc0(i * sizeof(ParamExecData));
+		/* ... and copy down all values, whether really needed or not */
+		while (--i >= 0)
+		{
+			/* copy value if any, but not execPlan link */
+			rcestate->es_param_exec_vals[i].value =
+				parentestate->es_param_exec_vals[i].value;
+			rcestate->es_param_exec_vals[i].isnull =
+				parentestate->es_param_exec_vals[i].isnull;
+		}
+	}
+
+	/*
+	 * Initialize private state information for each SubPlan.  We must do this
+	 * before running ExecInitNode on the main query tree, since
+	 * ExecInitSubPlan expects to be able to find these entries. Some of the
+	 * SubPlans might not be used in the part of the plan tree we intend to
+	 * run, but since it's not easy to tell which, we just initialize them
+	 * all.
+	 */
+	Assert(rcestate->es_subplanstates == NIL);
+	foreach(l, parentestate->es_plannedstmt->subplans)
+	{
+		Plan	   *subplan = (Plan *) lfirst(l);
+		PlanState  *subplanstate;
+
+		subplanstate = ExecInitNode(subplan, rcestate, 0);
+		rcestate->es_subplanstates = lappend(rcestate->es_subplanstates,
+											 subplanstate);
+	}
+
+	/*
+	 * Build an RTI indexed array of rowmarks, so that
+	 * EvalPlanQualFetchRowMark() can efficiently access the to be fetched
+	 * rowmark.
+	 */
+	epqstate->relsubs_rowmark = (ExecAuxRowMark **)
+		palloc0(rtsize * sizeof(ExecAuxRowMark *));
+	foreach(l, epqstate->arowMarks)
+	{
+		ExecAuxRowMark *earm = (ExecAuxRowMark *) lfirst(l);
+
+		epqstate->relsubs_rowmark[earm->rowmark->rti - 1] = earm;
+	}
+
+	/*
+	 * Initialize per-relation EPQ tuple states to not-fetched.
+	 */
+	epqstate->relsubs_done = (bool *)
+		palloc0(rtsize * sizeof(bool));
+
+	/*
+	 * Initialize the private state information for all the nodes in the part
+	 * of the plan tree we need to run.  This opens files, allocates storage
+	 * and leaves us ready to start processing tuples.
+	 */
+	epqstate->recheckplanstate = ExecInitNode(planTree, rcestate, 0);
+
+	MemoryContextSwitchTo(oldcontext);
+}
+
+/*
+ * EvalPlanQualEnd -- shut down at termination of parent plan state node,
+ * or if we are done with the current EPQ child.
+ *
+ * This is a cut-down version of ExecutorEnd(); basically we want to do most
+ * of the normal cleanup, but *not* close result relations (which we are
+ * just sharing from the outer query).  We do, however, have to close any
+ * result and trigger target relations that got opened, since those are not
+ * shared.  (There probably shouldn't be any of the latter, but just in
+ * case...)
+ */
+void
+EvalPlanQualEnd(EPQState *epqstate)
+{
+	EState	   *estate = epqstate->recheckestate;
+	Index		rtsize;
+	MemoryContext oldcontext;
+	ListCell   *l;
+
+	rtsize = epqstate->parentestate->es_range_table_size;
+
+	/*
+	 * We may have a tuple table, even if EPQ wasn't started, because we allow
+	 * use of EvalPlanQualSlot() without calling EvalPlanQualBegin().
+	 */
+	if (epqstate->tuple_table != NIL)
+	{
+		memset(epqstate->relsubs_slot, 0,
+			   rtsize * sizeof(TupleTableSlot *));
+		ExecResetTupleTable(epqstate->tuple_table, true);
+		epqstate->tuple_table = NIL;
+	}
+
+	/* EPQ wasn't started, nothing further to do */
+	if (estate == NULL)
+		return;
+
+	oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
+
+	ExecEndNode(epqstate->recheckplanstate);
+
+	foreach(l, estate->es_subplanstates)
+	{
+		PlanState  *subplanstate = (PlanState *) lfirst(l);
+
+		ExecEndNode(subplanstate);
+	}
+
+	/* throw away the per-estate tuple table, some node may have used it */
+	ExecResetTupleTable(estate->es_tupleTable, false);
+
+	/* Close any result and trigger target relations attached to this EState */
+	ExecCloseResultRelations(estate);
+
+	MemoryContextSwitchTo(oldcontext);
+
+	FreeExecutorState(estate);
+
+	/* Mark EPQState idle */
+	epqstate->origslot = NULL;
+	epqstate->recheckestate = NULL;
+	epqstate->recheckplanstate = NULL;
+	epqstate->relsubs_rowmark = NULL;
+	epqstate->relsubs_done = NULL;
+}

nodeSeqscan.c

+/*-------------------------------------------------------------------------
+ *
+ * nodeSeqscan.c
+ *	  Support routines for sequential scans of relations.
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/executor/nodeSeqscan.c
+ *
+ *-------------------------------------------------------------------------
+ */
+/*
+ * INTERFACE ROUTINES
+ *		ExecSeqScan				sequentially scans a relation.
+ *		ExecSeqNext				retrieve next tuple in sequential order.
+ *		ExecInitSeqScan			creates and initializes a seqscan node.
+ *		ExecEndSeqScan			releases any storage allocated.
+ *		ExecReScanSeqScan		rescans the relation
+ *
+ *		ExecSeqScanEstimate		estimates DSM space needed for parallel scan
+ *		ExecSeqScanInitializeDSM initialize DSM for parallel scan
+ *		ExecSeqScanReInitializeDSM reinitialize DSM for fresh parallel scan
+ *		ExecSeqScanInitializeWorker attach to DSM info in parallel worker
+ */
+#include "postgres.h"
+
+#include "access/relscan.h"
+#include "access/tableam.h"
+#include "executor/execdebug.h"
+#include "executor/nodeSeqscan.h"
+#include "nodes/nodes.h"
+#include "utils/rel.h"
+/* CS631 start */
+/* Including SPI for executing the insert statements into AIDX_QUERIES table */
+#include "executor/spi.h"
+/* Including for CMDType struct use */
+#include "executor/execExpr.h"
+/* CS631 end */
+
+static TupleTableSlot *SeqNext(SeqScanState *node);
+
+
+/* ----------------------------------------------------------------
+ *						Scan Support
+ * ----------------------------------------------------------------
+ */
+
+/* ----------------------------------------------------------------
+ *		SeqNext
+ *
+ *		This is a workhorse for ExecSeqScan
+ * ----------------------------------------------------------------
+ */
+static TupleTableSlot *
+SeqNext(SeqScanState *node)
+{
+	TableScanDesc scandesc;
+	EState	   *estate;
+	ScanDirection direction;
+	TupleTableSlot *slot;
+
+	/*
+	 * get information from the estate and scan state
+	 */
+	scandesc = node->ss.ss_currentScanDesc;
+	estate = node->ss.ps.state;
+	direction = estate->es_direction;
+	slot = node->ss.ss_ScanTupleSlot;
+
+	if (scandesc == NULL)
+	{
+		/*
+		 * We reach here if the scan is not parallel, or if we're serially
+		 * executing a scan that was planned to be parallel.
+		 */
+		scandesc = table_beginscan(node->ss.ss_currentRelation,
+								   estate->es_snapshot,
+								   0, NULL);
+		node->ss.ss_currentScanDesc = scandesc;
+	}
+
+	/*
+	 * get the next tuple from the table
+	 */
+	if (table_scan_getnextslot(scandesc, direction, slot))
+		return slot;
+	return NULL;
+}
+
+/*
+ * SeqRecheck -- access method routine to recheck a tuple in EvalPlanQual
+ */
+static bool
+SeqRecheck(SeqScanState *node, TupleTableSlot *slot)
+{
+	/*
+	 * Note that unlike IndexScan, SeqScan never use keys in heap_beginscan
+	 * (and this is very bad) - so, here we do not check are keys ok or not.
+	 */
+	return true;
+}
+
+/* ----------------------------------------------------------------
+ *		ExecSeqScan(node)
+ *
+ *		Scans the relation sequentially and returns the next qualifying
+ *		tuple.
+ *		We call the ExecScan() routine and pass it the appropriate
+ *		access method functions.
+ * ----------------------------------------------------------------
+ */
+static TupleTableSlot *
+ExecSeqScan(PlanState *pstate)
+{
+	SeqScanState *node = castNode(SeqScanState, pstate);
+
+	return ExecScan(&node->ss,
+					(ExecScanAccessMtd) SeqNext,
+					(ExecScanRecheckMtd) SeqRecheck);
+}
+
+
+/* ----------------------------------------------------------------
+ *		ExecInitSeqScan
+ * ----------------------------------------------------------------
+ */
+SeqScanState *
+ExecInitSeqScan(SeqScan *node, EState *estate, int eflags)
+{
+	SeqScanState *scanstate;
+
+	/*
+	 * Once upon a time it was possible to have an outerPlan of a SeqScan, but
+	 * not any more.
+	 */
+	Assert(outerPlan(node) == NULL);
+	Assert(innerPlan(node) == NULL);
+
+	/*
+	 * create state structure
+	 */
+	scanstate = makeNode(SeqScanState);
+	scanstate->ss.ps.plan = (Plan *) node;
+	scanstate->ss.ps.state = estate;
+	scanstate->ss.ps.ExecProcNode = ExecSeqScan;
+
+
+	/*
+	 * Miscellaneous initialization
+	 *
+	 * create expression context for node
+	 */
+	ExecAssignExprContext(estate, &scanstate->ss.ps);
+
+	/*
+	 * open the scan relation
+	 */
+	scanstate->ss.ss_currentRelation =
+		ExecOpenScanRelation(estate,
+							 node->scanrelid,
+							 eflags);
+
+/* CS631 start */
+	/*
+	 * Eg: SELECT * FROM PG_DATABASE
+	 * Relation name => scanstate->ss.ss_currentRelation->rd_rel->relname.data === PG_DATABASE
+	 */
+	char* relName = "";
+
+	// Relation Name
+	relName = scanstate->ss.ss_currentRelation->rd_rel->relname.data;
+
+	elog(LOG, "%s", relName);
+/* CS631 end */
+
+	/* and create slot with the appropriate rowtype */
+	ExecInitScanTupleSlot(estate, &scanstate->ss,
+						  RelationGetDescr(scanstate->ss.ss_currentRelation),
+						  table_slot_callbacks(scanstate->ss.ss_currentRelation));
+
+/* CS631 start */
+	/*
+	 * List of Attributes selected => scanstate->ss.ss_ScanTupleSlot->tts_tupleDescriptor->attrs
+	 */
+	TupleDescData *all_selected_attributes = scanstate->ss.ss_ScanTupleSlot->tts_tupleDescriptor;
+
+	elog(LOG, "%d", all_selected_attributes->natts);
+
+	FormData_pg_attribute *attrs = all_selected_attributes->attrs;
+
+	char attr_selected[1000] = "";
+	int j, l, final_string_length, k, ret;
+	char final_attrs[1000] = "";
+
+	char *comma = ",", *eos="\0";
+	for (int i=0; i<all_selected_attributes->natts; i++){
+		j = strlen(attr_selected);
+		l = 0;
+		final_string_length = strlen(final_attrs);
+		for(k=strlen(final_attrs); k<strlen(attrs[i].attname.data)+final_string_length; k++){
+			final_attrs[k] = attrs[i].attname.data[l++];
+		}
+		final_attrs[k] = comma[0];
+	}
+	final_attrs[k] = eos[0];
+	elog(LOG, "%s", final_attrs);
+/* CS631 end */
+
+
+	/*
+	 * Initialize result type and projection.
+	 */
+	ExecInitResultTypeTL(&scanstate->ss.ps);
+	ExecAssignScanProjectionInfo(&scanstate->ss);
+
+	/*
+	 * initialize child expressions
+	 */
+	scanstate->ss.ps.qual =
+		ExecInitQual(node->plan.qual, (PlanState *) scanstate);
+/* CS631 start */
+	/*
+	 * Creating the INSERT query for inserting data into AIDX_QUERIES table
+	 * AIDX_QUERIES(
+	 * 		type varchar(100), -- Type of the query - select/delete/insert
+	 * 		tablename varchar(100), -- Table name
+	 * 		attrs varchar(100) -- attributes in the where clause (currently for insert we insert * in the table))
+	 * 
+	 *
+	 */
+
+	char new_new_query[200] = "INSERT INTO AIDX_QUERIES VALUES('";
+	char *type="";
+	char *add1 = "','";
+	char *add2 = "','";
+	char *add3 = "');";
+	char qual_attr[100] = "";
+	if(scanstate->ss.ps.qual!= NULL){
+		int attnum = scanstate->ss.ps.qual->steps->d.var.attnum;
+
+	elog(LOG, "%d", attnum);
+
+
+	for(int i=0; i<strlen(attrs[attnum-1].attname.data); i++){
+		qual_attr[i] = attrs[attnum-1].attname.data[i];
+	}
+	elog(LOG, "%s", qual_attr);
+
+	/*Retrieving the Type of the query*/
+	if(estate->es_plannedstmt->commandType == CMD_SELECT){
+		type =  "select";
+		elog(LOG,"CMDTYPE SELECT \n");
+	}
+	if(estate->es_plannedstmt->commandType == CMD_DELETE){
+		type =  "delete";
+		elog(LOG,"CMDTYPE DELTE \n");
+	}
+	}
+	else if(scanstate->ss.ps.qual == NULL && estate->es_plannedstmt->commandType == CMD_DELETE){
+		qual_attr[0] = '*';
+		type="delete";
+
+	}
+
+	int i1;
+
+	int j1 = strlen(new_new_query);
+
+	for (i1 = 0; type[i1] != '\0'; i1++) {
+		new_new_query[i1 + j1] = type[i1];
+	}
+
+	j1 = strlen(new_new_query);
+
+	for (i1 = 0; add1[i1] != '\0'; i1++) {
+			new_new_query[i1 + j1] = add1[i1];
+	}
+
+	j1 = strlen(new_new_query);
+
+	for (i1 = 0; relName[i1] != '\0'; i1++) {
+			new_new_query[i1 + j1] = relName[i1];
+	}
+
+	j1 = strlen(new_new_query);
+
+	for (i1 = 0; add2[i1] != '\0'; i1++) {
+			new_new_query[i1 + j1] = add2[i1];
+	}
+
+	j1 = strlen(new_new_query);
+
+	for (i1 = 0; qual_attr[i1] != '\0'; i1++) {
+			new_new_query[i1 + j1] = qual_attr[i1];
+	}
+
+	j1 = strlen(new_new_query);
+
+	for (i1 = 0; add3[i1] != '\0'; i1++) {
+			new_new_query[i1 + j1] = add3[i1];
+	}
+
+	new_new_query[i1 + j1] = '\0';
+
+	elog(LOG, "%s", new_new_query);
+
+	if(type == "select" || type == "delete")
+		if( SPI_connect() == SPI_OK_CONNECT )
+		{
+			ret = SPI_execute(new_new_query,false,0);
+			ret = SPI_finish();
+		}
+/* CS631 end */
+
+	return scanstate;
+}
+
+/* ----------------------------------------------------------------
+ *		ExecEndSeqScan
+ *
+ *		frees any storage allocated through C routines.
+ * ----------------------------------------------------------------
+ */
+void
+ExecEndSeqScan(SeqScanState *node)
+{
+	TableScanDesc scanDesc;
+
+	/*
+	 * get information from node
+	 */
+	scanDesc = node->ss.ss_currentScanDesc;
+
+	/*
+	 * Free the exprcontext
+	 */
+	ExecFreeExprContext(&node->ss.ps);
+
+	/*
+	 * clean out the tuple table
+	 */
+	if (node->ss.ps.ps_ResultTupleSlot)
+		ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
+	ExecClearTuple(node->ss.ss_ScanTupleSlot);
+
+	/*
+	 * close heap scan
+	 */
+	if (scanDesc != NULL)
+		table_endscan(scanDesc);
+}
+
+/* ----------------------------------------------------------------
+ *						Join Support
+ * ----------------------------------------------------------------
+ */
+
+/* ----------------------------------------------------------------
+ *		ExecReScanSeqScan
+ *
+ *		Rescans the relation.
+ * ----------------------------------------------------------------
+ */
+void
+ExecReScanSeqScan(SeqScanState *node)
+{
+	TableScanDesc scan;
+
+	scan = node->ss.ss_currentScanDesc;
+
+	if (scan != NULL)
+		table_rescan(scan,		/* scan desc */
+					 NULL);		/* new scan keys */
+
+	ExecScanReScan((ScanState *) node);
+}
+
+/* ----------------------------------------------------------------
+ *						Parallel Scan Support
+ * ----------------------------------------------------------------
+ */
+
+/* ----------------------------------------------------------------
+ *		ExecSeqScanEstimate
+ *
+ *		Compute the amount of space we'll need in the parallel
+ *		query DSM, and inform pcxt->estimator about our needs.
+ * ----------------------------------------------------------------
+ */
+void
+ExecSeqScanEstimate(SeqScanState *node,
+					ParallelContext *pcxt)
+{
+	EState	   *estate = node->ss.ps.state;
+
+	node->pscan_len = table_parallelscan_estimate(node->ss.ss_currentRelation,
+												  estate->es_snapshot);
+	shm_toc_estimate_chunk(&pcxt->estimator, node->pscan_len);
+	shm_toc_estimate_keys(&pcxt->estimator, 1);
+}
+
+/* ----------------------------------------------------------------
+ *		ExecSeqScanInitializeDSM
+ *
+ *		Set up a parallel heap scan descriptor.
+ * ----------------------------------------------------------------
+ */
+void
+ExecSeqScanInitializeDSM(SeqScanState *node,
+						 ParallelContext *pcxt)
+{
+	EState	   *estate = node->ss.ps.state;
+	ParallelTableScanDesc pscan;
+
+	pscan = shm_toc_allocate(pcxt->toc, node->pscan_len);
+	table_parallelscan_initialize(node->ss.ss_currentRelation,
+								  pscan,
+								  estate->es_snapshot);
+	shm_toc_insert(pcxt->toc, node->ss.ps.plan->plan_node_id, pscan);
+	node->ss.ss_currentScanDesc =
+		table_beginscan_parallel(node->ss.ss_currentRelation, pscan);
+}
+
+/* ----------------------------------------------------------------
+ *		ExecSeqScanReInitializeDSM
+ *
+ *		Reset shared state before beginning a fresh scan.
+ * ----------------------------------------------------------------
+ */
+void
+ExecSeqScanReInitializeDSM(SeqScanState *node,
+						   ParallelContext *pcxt)
+{
+	ParallelTableScanDesc pscan;
+
+	pscan = node->ss.ss_currentScanDesc->rs_parallel;
+	table_parallelscan_reinitialize(node->ss.ss_currentRelation, pscan);
+}
+
+/* ----------------------------------------------------------------
+ *		ExecSeqScanInitializeWorker
+ *
+ *		Copy relevant information from TOC into planstate.
+ * ----------------------------------------------------------------
+ */
+void
+ExecSeqScanInitializeWorker(SeqScanState *node,
+							ParallelWorkerContext *pwcxt)
+{
+	ParallelTableScanDesc pscan;
+
+	pscan = shm_toc_lookup(pwcxt->toc, node->ss.ps.plan->plan_node_id, false);
+	node->ss.ss_currentScanDesc =
+		table_beginscan_parallel(node->ss.ss_currentRelation, pscan);
+}

worker_spi/.gitignore

+# Generated subdirectories
+/log/
+/results/
+/tmp_check/

worker_spi/Makefile

+# src/test/modules/worker_spi/Makefile
+
+MODULES = worker_spi
+
+EXTENSION = worker_spi
+DATA = worker_spi--1.0.sql
+PGFILEDESC = "worker_spi - background worker example"
+
+REGRESS = worker_spi
+
+# enable our module in shared_preload_libraries for dynamic bgworkers
+REGRESS_OPTS = --temp-config $(top_srcdir)/contrib/worker_spi/dynamic.conf
+
+# Disable installcheck to ensure we cover dynamic bgworkers.
+NO_INSTALLCHECK = 1
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = contrib/worker_spi
+top_builddir = ../../
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif

worker_spi/dynamic.conf

+shared_preload_libraries = worker_spi
+worker_spi.database = contrib_regression

worker_spi/expected/worker_spi.out

+CREATE EXTENSION worker_spi;
+SELECT worker_spi_launch(4) IS NOT NULL;
+ ?column? 
+----------
+ t
+(1 row)
+
+-- wait until the worker completes its initialization
+DO $$
+DECLARE
+	visible bool;
+	loops int := 0;
+BEGIN
+	LOOP
+		visible := table_name IS NOT NULL
+			FROM information_schema.tables
+			WHERE table_schema = 'schema4' AND table_name = 'counted';
+		IF visible OR loops > 120 * 10 THEN EXIT; END IF;
+		PERFORM pg_sleep(0.1);
+		loops := loops + 1;
+	END LOOP;
+END
+$$;
+INSERT INTO schema4.counted VALUES ('total', 0), ('delta', 1);
+SELECT pg_reload_conf();
+ pg_reload_conf 
+----------------
+ t
+(1 row)
+
+-- wait until the worker has processed the tuple we just inserted
+DO $$
+DECLARE
+	count int;
+	loops int := 0;
+BEGIN
+	LOOP
+		count := count(*) FROM schema4.counted WHERE type = 'delta';
+		IF count = 0 OR loops > 120 * 10 THEN EXIT; END IF;
+		PERFORM pg_sleep(0.1);
+		loops := loops + 1;
+	END LOOP;
+END
+$$;
+SELECT * FROM schema4.counted;
+ type  | value 
+-------+-------
+ total |     1
+(1 row)
+

worker_spi/sql/worker_spi.sql

+CREATE EXTENSION worker_spi;
+SELECT worker_spi_launch(4) IS NOT NULL;
+-- wait until the worker completes its initialization
+DO $$
+DECLARE
+	visible bool;
+	loops int := 0;
+BEGIN
+	LOOP
+		visible := table_name IS NOT NULL
+			FROM information_schema.tables
+			WHERE table_schema = 'schema4' AND table_name = 'counted';
+		IF visible OR loops > 120 * 10 THEN EXIT; END IF;
+		PERFORM pg_sleep(0.1);
+		loops := loops + 1;
+	END LOOP;
+END
+$$;
+INSERT INTO schema4.counted VALUES ('total', 0), ('delta', 1);
+SELECT pg_reload_conf();
+-- wait until the worker has processed the tuple we just inserted
+DO $$
+DECLARE
+	count int;
+	loops int := 0;
+BEGIN
+	LOOP
+		count := count(*) FROM schema4.counted WHERE type = 'delta';
+		IF count = 0 OR loops > 120 * 10 THEN EXIT; END IF;
+		PERFORM pg_sleep(0.1);
+		loops := loops + 1;
+	END LOOP;
+END
+$$;
+SELECT * FROM schema4.counted;

worker_spi/worker_spi--1.0.sql

+/* src/test/modules/worker_spi/worker_spi--1.0.sql */
+
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION worker_spi" to load this file. \quit
+
+CREATE FUNCTION worker_spi_launch(pg_catalog.int4)
+RETURNS pg_catalog.int4 STRICT
+AS 'MODULE_PATHNAME'
+LANGUAGE C;

worker_spi/worker_spi.c

+/* -------------------------------------------------------------------------
+ *
+ * worker_spi.c
+ *		Sample background worker code that demonstrates various coding
+ *		patterns: establishing a database connection; starting and committing
+ *		transactions; using GUC variables, and heeding SIGHUP to reread
+ *		the configuration file; reporting to pg_stat_activity; using the
+ *		process latch to sleep and exit in case of postmaster death.
+ *
+ * This code connects to a database, creates a schema and table, and summarizes
+ * the numbers contained therein.  To see it working, insert an initial value
+ * with "total" type and some initial value; then insert some other rows with
+ * "delta" type.  Delta rows will be deleted by this worker and their values
+ * aggregated into the total.
+ *
+ * Copyright (c) 2013-2020, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *		src/test/modules/worker_spi/worker_spi.c
+ *
+ * -------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+/* These are always necessary for a bgworker */
+#include "miscadmin.h"
+#include "postmaster/bgworker.h"
+#include "storage/ipc.h"
+#include "storage/latch.h"
+#include "storage/lwlock.h"
+#include "storage/proc.h"
+#include "storage/shmem.h"
+
+/* these headers are used by this particular worker's code */
+#include "access/xact.h"
+#include "executor/spi.h"
+#include "fmgr.h"
+#include "lib/stringinfo.h"
+#include "pgstat.h"
+#include "utils/builtins.h"
+#include "utils/snapmgr.h"
+#include "tcop/utility.h"
+
+PG_MODULE_MAGIC;
+
+PG_FUNCTION_INFO_V1(worker_spi_launch);
+
+void		_PG_init(void);
+void		worker_spi_main(Datum) pg_attribute_noreturn();
+
+/* flags set by signal handlers */
+static volatile sig_atomic_t got_sighup = false;
+static volatile sig_atomic_t got_sigterm = false;
+
+/* GUC variables */
+static int	worker_spi_naptime = 0;
+static int	worker_spi_total_workers = 1;
+static char *worker_spi_database = NULL;
+
+
+typedef struct worktable
+{
+	const char *schema;
+	const char *name;
+} worktable;
+
+/* CS631 start */
+// Function to iterate through the output of the query executed by SPI
+const char* outExecResult(int ret)
+{
+    int64 rows = 0;
+    int i = 0;
+    int j = 0;
+	char * new_query;
+    if(ret <= 0)
+        return;
+    rows = SPI_processed; // number of rows returned
+	// SPI_tuptable is a structure that holds the result of the query
+    if (SPI_tuptable)
+    {
+        TupleDesc       tupdesc = SPI_tuptable->tupdesc;
+        SPITupleTable   *tuptable = SPI_tuptable;
+        char            buf[8192] = {0};
+		// For loop to iterate through the rows
+        for (i = 1; i <= tupdesc->natts; i++)
+        {
+            char    *value = NULL;
+            char    *type = NULL;
+            char    *inter = (i == tupdesc->natts) ? " " : " |";
+            char    *cur_loc = buf + strlen (buf);
+            int     remain_base = sizeof(buf) - strlen(buf);
+            value = SPI_fname(tupdesc, i);
+            type = SPI_gettype(tupdesc, i);
+        }
+		int assign_var = 0;
+		int assign_max_size = 8192;
+		// For loop to iterate over stored tuples and over columns
+        for (j = 0; j < rows; j++)
+        {
+            HeapTuple   tuple = tuptable->vals[j];
+            for (int i = 0; i < 8192; i++){
+              buf[i] = 0;
+            }
+
+    		char* rel,*att; // relation and attribute
+
+            for (i = 1; i <= tupdesc->natts; i++)
+            {
+                char    *temp_value = NULL;
+                char    *inter = (i == tupdesc->natts) ? " " : " |";
+                char    *cur_loc = buf + strlen (buf);
+                int     remain_base = sizeof(buf) - strlen(buf);
+
+                temp_value = SPI_getvalue(tuple, tupdesc, i);
+                if(i==1){
+                	rel = temp_value; // relation
+                }
+                if(i==2){
+                	att = temp_value; // attribute
+                }
+
+            }
+            if(j==1){
+				//Initialize the query
+        		sprintf(new_query,"CREATE INDEX IF NOT EXISTS %s_%s ON %s(%s);\n",rel,att,rel,att);
+
+            }
+            else{
+				//Appending to the original query
+        		sprintf(new_query,"CREATE INDEX IF NOT EXISTS %s_%s ON %s(%s);\n%s",rel,att,rel,att,new_query);
+
+            }
+            //printf("%s\n",new_query);
+            //fflush(stdout);
+        }
+    }
+    printf("Returning index query\n%s\n",new_query);
+    fflush(stdout);
+    return new_query;
+}
+
+// Function to execute and sql query string
+static void
+my_exec_spi(char *sql)
+{
+    int ret = 0;
+    printf("%s = SQL STATEMENT", sql);
+	fflush(stdout);
+	ret = SPI_execute(sql, false, 0);
+    //outExecResult(ret);
+}
+
+/* CS631 end */
+
+
+/*
+ * Signal handler for SIGTERM
+ *		Set a flag to let the main loop to terminate, and set our latch to wake
+ *		it up.
+ */
+static void
+worker_spi_sigterm(SIGNAL_ARGS)
+{
+	int			save_errno = errno;
+
+	got_sigterm = true;
+	SetLatch(MyLatch);
+
+	errno = save_errno;
+}
+
+/*
+ * Signal handler for SIGHUP
+ *		Set a flag to tell the main loop to reread the config file, and set
+ *		our latch to wake it up.
+ */
+static void
+worker_spi_sighup(SIGNAL_ARGS)
+{
+	int			save_errno = errno;
+
+	got_sighup = true;
+	SetLatch(MyLatch);
+
+	errno = save_errno;
+}
+
+/*
+ * Initialize workspace for a worker process: create the schema if it doesn't
+ * already exist.
+ */
+static void
+initialize_worker_spi(worktable *table)
+{
+	int			ret;
+	int			ntup;
+	bool		isnull;
+	StringInfoData buf;
+
+	SetCurrentStatementStartTimestamp();
+	StartTransactionCommand();
+	SPI_connect();
+	PushActiveSnapshot(GetTransactionSnapshot());
+	pgstat_report_activity(STATE_RUNNING, "initializing worker_spi schema");
+
+	/* XXX could we use CREATE SCHEMA IF NOT EXISTS? */
+	initStringInfo(&buf);
+	appendStringInfo(&buf, "select count(*) from pg_namespace where nspname = '%s'",
+					 table->schema);
+	//appendStringInfo(&buf,"select * from AIDX_QUERIES");
+	ret = SPI_execute(buf.data, true, 0);
+	if (ret != SPI_OK_SELECT)
+		elog(FATAL, "SPI_execute failed: error code %d", ret);
+
+	if (SPI_processed != 1)
+		elog(FATAL, "not a singleton result");
+
+	ntup = DatumGetInt64(SPI_getbinval(SPI_tuptable->vals[0],
+									   SPI_tuptable->tupdesc,
+									   1, &isnull));
+	if (isnull)
+		elog(FATAL, "null result");
+
+	if (ntup == 0)
+	{
+		resetStringInfo(&buf);
+		appendStringInfo(&buf,
+						 "CREATE SCHEMA \"%s\" "
+						 "CREATE TABLE \"%s\" ("
+						 "		type text CHECK (type IN ('total', 'delta')), "
+						 "		value	integer)"
+						 "CREATE UNIQUE INDEX \"%s_unique_total\" ON \"%s\" (type) "
+						 "WHERE type = 'total'",
+						 table->schema, table->name, table->name, table->name);
+
+		//appendStringInfo(&buf,"SELECT * FROM AIDX_QUERIES");
+		/* set statement start time */
+		elog(LOG,"WORKER IS RUNNING");
+		printf("WORKER RUNNING");
+		SetCurrentStatementStartTimestamp();
+
+		ret = SPI_execute(buf.data, false, 0);
+
+		if (ret != SPI_OK_UTILITY)
+			elog(FATAL, "failed to create my schema");
+	}
+
+	SPI_finish();
+	PopActiveSnapshot();
+	CommitTransactionCommand();
+	pgstat_report_activity(STATE_IDLE, NULL);
+}
+
+void
+worker_spi_main(Datum main_arg)
+{
+	int			index = DatumGetInt32(main_arg);
+	worktable  *table;
+	StringInfoData buf;
+	char		name[20];
+
+	table = palloc(sizeof(worktable));
+	sprintf(name, "schema%d", index);
+	table->schema = pstrdup(name);
+	table->name = pstrdup("counted");
+
+	/* Establish signal handlers before unblocking signals. */
+	pqsignal(SIGHUP, worker_spi_sighup);
+	pqsignal(SIGTERM, worker_spi_sigterm);
+
+	/* We're now ready to receive signals */
+	BackgroundWorkerUnblockSignals();
+
+	/* Connect to our database */
+	BackgroundWorkerInitializeConnection(worker_spi_database, NULL, 0);
+
+	elog(LOG, "%s initialized with %s.%s",
+		 MyBgworkerEntry->bgw_name, table->schema, table->name);
+	initialize_worker_spi(table);
+
+	/*
+	 * Quote identifiers passed to us.  Note that this must be done after
+	 * initialize_worker_spi, because that routine assumes the names are not
+	 * quoted.
+	 *
+	 * Note some memory might be leaked here.
+	 */
+	table->schema = quote_identifier(table->schema);
+	table->name = quote_identifier(table->name);
+
+	initStringInfo(&buf);
+//	appendStringInfo(&buf,
+//					 "WITH deleted AS (DELETE "
+//					 "FROM %s.%s "
+//					 "WHERE type = 'delta' RETURNING value), "
+//					 "total AS (SELECT coalesce(sum(value), 0) as sum "
+//					 "FROM deleted) "
+//					 "UPDATE %s.%s "
+//					 "SET value = %s.value + total.sum "
+//					 "FROM total WHERE type = 'total' "
+//					 "RETURNING %s.value;",
+//					 table->schema, table->name,
+//					 table->schema, table->name,
+//					 table->name,
+//					 table->name);
+	appendStringInfo(&buf,
+			"");
+
+
+	//appendStringInfo(&buf,"UPDATE AIDX_QUERIES set type = 'INSERT' where table_name='student'");
+	/*
+	 * Main loop: do this until the SIGTERM handler tells us to terminate
+	 */
+	int toggle = 0;
+	char* index_creation_query;
+	int	ret;
+	int ind_ret;
+	while (!got_sigterm)
+	{
+
+		/*
+		 * Background workers mustn't call usleep() or any direct equivalent:
+		 * instead, they may wait on their process latch, which sleeps as
+		 * necessary, but is awakened if postmaster dies.  That way the
+		 * background process goes away immediately in an emergency.
+		 */
+		(void) WaitLatch(MyLatch,
+						 WL_LATCH_SET | WL_TIMEOUT | WL_EXIT_ON_PM_DEATH,
+						 worker_spi_naptime * 1000L,
+						 PG_WAIT_EXTENSION);
+		ResetLatch(MyLatch);
+
+		CHECK_FOR_INTERRUPTS();
+
+		/*
+		 * In case of a SIGHUP, just reload the configuration.
+		 */
+		if (got_sighup)
+		{
+			got_sighup = false;
+			ProcessConfigFile(PGC_SIGHUP);
+		}
+
+		/*
+		 * Start a transaction on which we can run queries.  Note that each
+		 * StartTransactionCommand() call should be preceded by a
+		 * SetCurrentStatementStartTimestamp() call, which sets both the time
+		 * for the statement we're about the run, and also the transaction
+		 * start time.  Also, each other query sent to SPI should probably be
+		 * preceded by SetCurrentStatementStartTimestamp(), so that statement
+		 * start time is always up to date.
+		 *
+		 * The SPI_connect() call lets us run queries through the SPI manager,
+		 * and the PushActiveSnapshot() call creates an "active" snapshot
+		 * which is necessary for queries to have MVCC data to work on.
+		 *
+		 * The pgstat_report_activity() call makes our activity visible
+		 * through the pgstat views.
+		 */
+		SetCurrentStatementStartTimestamp();
+		StartTransactionCommand();
+		SPI_connect();
+		//if(toggle==0){
+		PushActiveSnapshot(GetTransactionSnapshot());
+		//}
+/* CS631 start */
+		/* We can now execute queries via SPI */
+	    char    *sql10 = "select table_name,attr,count(*) from aidx_queries group by table_name,attr;";
+	    if(toggle==0){
+			pgstat_report_activity(STATE_RUNNING,sql10 );
+	    	ret = SPI_execute(sql10, false, 0);
+	    	index_creation_query=outExecResult(ret);
+	    }
+	    else{
+			pgstat_report_activity(STATE_RUNNING, index_creation_query);
+			//printf("%d Meet\n",ret);
+			//fflush(stdout);
+			printf("INDEX TO CREATE:\n%s\n",index_creation_query);
+			fflush(stdout);
+			ind_ret = SPI_execute(index_creation_query,false,0);
+			printf("INDEX DONE STATUS = %d\n",ind_ret);
+			fflush(stdout);
+	    }
+/* CS631 end */
+
+
+		if (ret != SPI_OK_SELECT)
+			elog(FATAL, "cannot select from table %s.%s: error code %d",
+				 table->schema, table->name, ret);
+
+		if (SPI_processed > 0)
+		{
+			bool		isnull;
+			int32		val;
+
+			val = DatumGetInt32(SPI_getbinval(SPI_tuptable->vals[0],
+											  SPI_tuptable->tupdesc,
+											  1, &isnull));
+			//elog(LOG,"%s",SPI_tuptable->vals[0]);
+			if (!isnull)
+				elog(LOG, "%s: count in %s.%s is now %d",
+					 MyBgworkerEntry->bgw_name,
+					 table->schema, table->name, val);
+		}
+
+		/*
+		 * And finish our transaction.
+		 */
+		SPI_finish();
+		//if(toggle==0){
+		PopActiveSnapshot();
+		//}
+		CommitTransactionCommand();
+		pgstat_report_stat(false);
+		pgstat_report_activity(STATE_IDLE, NULL);
+
+
+
+
+
+//#######################################################################
+
+
+
+/* CS631 start */
+		toggle = 1-toggle;
+/* CS631 end */
+
+	}
+
+	proc_exit(1);
+}
+
+/*
+ * Entrypoint of this module.
+ *
+ * We register more than one worker process here, to demonstrate how that can
+ * be done.
+ */
+void
+_PG_init(void)
+{
+	BackgroundWorker worker;
+	unsigned int i;
+
+	/* get the configuration */
+	DefineCustomIntVariable("worker_spi.naptime",
+							"Duration between each check (in seconds).",
+							NULL,
+							&worker_spi_naptime,
+							20,
+							1,
+							INT_MAX,
+							PGC_SIGHUP,
+							0,
+							NULL,
+							NULL,
+							NULL);
+
+	if (!process_shared_preload_libraries_in_progress)
+		return;
+
+	DefineCustomIntVariable("worker_spi.total_workers",
+							"Number of workers.",
+							NULL,
+							&worker_spi_total_workers,
+							1,
+							1,
+							100,
+							PGC_POSTMASTER,
+							0,
+							NULL,
+							NULL,
+							NULL);
+
+	DefineCustomStringVariable("worker_spi.database",
+							   "Database to connect to.",
+							   NULL,
+							   &worker_spi_database,
+							   "postgres",
+							   PGC_POSTMASTER,
+							   0,
+							   NULL, NULL, NULL);
+
+	/* set up common data for all our workers */
+	memset(&worker, 0, sizeof(worker));
+	worker.bgw_flags = BGWORKER_SHMEM_ACCESS |
+		BGWORKER_BACKEND_DATABASE_CONNECTION;
+	worker.bgw_start_time = BgWorkerStart_RecoveryFinished;
+	worker.bgw_restart_time = BGW_NEVER_RESTART;
+	sprintf(worker.bgw_library_name, "worker_spi");
+	sprintf(worker.bgw_function_name, "worker_spi_main");
+	worker.bgw_notify_pid = 0;
+
+	/*
+	 * Now fill in worker-specific data, and do the actual registrations.
+	 */
+	for (i = 1; i <= worker_spi_total_workers; i++)
+	{
+		snprintf(worker.bgw_name, BGW_MAXLEN, "worker_spi worker %d", i);
+		snprintf(worker.bgw_type, BGW_MAXLEN, "worker_spi");
+		worker.bgw_main_arg = Int32GetDatum(i);
+
+		RegisterBackgroundWorker(&worker);
+	}
+}
+
+/*
+ * Dynamically launch an SPI worker.
+ */
+Datum
+worker_spi_launch(PG_FUNCTION_ARGS)
+{
+	int32		i = PG_GETARG_INT32(0);
+	BackgroundWorker worker;
+	BackgroundWorkerHandle *handle;
+	BgwHandleStatus status;
+	pid_t		pid;
+
+	memset(&worker, 0, sizeof(worker));
+	worker.bgw_flags = BGWORKER_SHMEM_ACCESS |
+		BGWORKER_BACKEND_DATABASE_CONNECTION;
+	worker.bgw_start_time = BgWorkerStart_RecoveryFinished;
+	worker.bgw_restart_time = BGW_NEVER_RESTART;
+	sprintf(worker.bgw_library_name, "worker_spi");
+	sprintf(worker.bgw_function_name, "worker_spi_main");
+	snprintf(worker.bgw_name, BGW_MAXLEN, "worker_spi worker %d", i);
+	snprintf(worker.bgw_type, BGW_MAXLEN, "worker_spi");
+	worker.bgw_main_arg = Int32GetDatum(i);
+	/* set bgw_notify_pid so that we can use WaitForBackgroundWorkerStartup */
+	worker.bgw_notify_pid = MyProcPid;
+
+	if (!RegisterDynamicBackgroundWorker(&worker, &handle))
+		PG_RETURN_NULL();
+
+	status = WaitForBackgroundWorkerStartup(handle, &pid);
+
+	if (status == BGWH_STOPPED)
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_RESOURCES),
+				 errmsg("could not start background process"),
+				 errhint("More details may be available in the server log.")));
+	if (status == BGWH_POSTMASTER_DIED)
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_RESOURCES),
+				 errmsg("cannot start background processes without postmaster"),
+				 errhint("Kill all remaining database processes and restart the database.")));
+	Assert(status == BGWH_STARTED);
+
+	PG_RETURN_INT32(pid);
+}

worker_spi/worker_spi.control

+# worker_spi extension
+comment = 'Sample background worker'
+default_version = '1.0'
+module_pathname = '$libdir/worker_spi'
+relocatable = true