Avoid checking permission of Babelfish temp tables on parallel worker

src/backend/executor/execMain.c

@@ -70,6 +70,8 @@ ExecutorEnd_hook_type ExecutorEnd_hook = NULL;
 
 TriggerRecuresiveCheck_hook_type TriggerRecuresiveCheck_hook = NULL;
 check_rowcount_hook_type check_rowcount_hook = NULL;
+ExecCheckOneRelPerms_hook_type ExecCheckOneRelPerms_hook = NULL;
+
 /* Hook for plugin to get control in ExecCheckPermissions() */
 ExecutorCheckPerms_hook_type ExecutorCheckPerms_hook = NULL;
 
@@ -648,6 +650,19 @@ ExecCheckOneRelPerms(RTEPermissionInfo *perminfo)
 	requiredPerms = perminfo->requiredPerms;
 	Assert(requiredPerms != 0);
 
+	/* 
+	 * Babelfish specific logic - Babelfish temp table is implemented
+	 * using ENR which is not shared with parallel worker and parallel
+	 * operations are not allowed for temp table in Postgres. Babelfish
+	 * can skip permission check for such use cases under parallel worker
+	 * using this hook.
+	 * Note - This hook must not be used outside of Babelfish parallel worker
+	 */
+	if (IsBabelfishParallelWorker() &&
+		ExecCheckOneRelPerms_hook &&
+		(*ExecCheckOneRelPerms_hook)(perminfo))
+		return true;
+
 	/*
 	 * userid to check as: current user unless we have a setuid indication.
 	 *
@@ -840,10 +855,9 @@ InitPlan(QueryDesc *queryDesc, int eflags)
 	int			i;
 
 	/*
-	 * Do permissions checks if not Babelfish parallel worker
+	 * Do permissions checks
 	 */
-	if (!IsBabelfishParallelWorker())
-		ExecCheckPermissions(rangeTable, plannedstmt->permInfos, true);
+	ExecCheckPermissions(rangeTable, plannedstmt->permInfos, true);
 
 	/*
 	 * initialize the node's execution state
@@ -3046,3 +3060,12 @@ EvalPlanQualEnd(EPQState *epqstate)
 	epqstate->relsubs_done = NULL;
 	epqstate->relsubs_blocked = NULL;
 }
+
+/*
+ * ExecCheckOneRelPerms_wrapper - wrapper around ExecCheckOneRelPerms
+ */
+bool
+ExecCheckOneRelPerms_wrapper(RTEPermissionInfo *perminfo)
+{
+	return ExecCheckOneRelPerms(perminfo);
+}

src/backend/executor/execParallel.c

@@ -122,6 +122,9 @@ typedef struct ExecParallelInitializeDSMContext
 	int			nnodes;
 } ExecParallelInitializeDSMContext;
 
+ExecInitParallelPlan_hook_type ExecInitParallelPlan_hook = NULL;
+ParallelQueryMain_hook_type ParallelQueryMain_hook = NULL;
+
 /* Helper functions that run in the parallel leader. */
 static char *ExecSerializePlan(Plan *plan, EState *estate);
 static bool ExecParallelEstimate(PlanState *planstate,
@@ -683,6 +686,12 @@ ExecInitParallelPlan(PlanState *planstate, EState *estate,
 						   mul_size(PARALLEL_TUPLE_QUEUE_SIZE, pcxt->nworkers));
 	shm_toc_estimate_keys(&pcxt->estimator, 1);
 
+	/* Let extension estimate a dynamic shared memory needed to communicate additional context */
+	if (ExecInitParallelPlan_hook)
+	{
+		(*ExecInitParallelPlan_hook)(estate, pcxt, true);
+	}
+
 	/*
 	 * Give parallel-aware nodes a chance to add to the estimates, and get a
 	 * count of how many PlanState nodes there are.
@@ -773,6 +782,12 @@ ExecInitParallelPlan(PlanState *planstate, EState *estate,
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_WAL_USAGE, walusage_space);
 	pei->wal_usage = walusage_space;
 
+	/* Give extension a chance to share additional context */
+	if (ExecInitParallelPlan_hook)
+	{
+		(*ExecInitParallelPlan_hook)(estate, pcxt,false);
+	}
+
 	/* Set up the tuple queues that the workers will write into. */
 	pei->tqueue = ExecParallelSetupTupleQueues(pcxt, false);
 
@@ -1433,6 +1448,12 @@ ParallelQueryMain(dsm_segment *seg, shm_toc *toc)
 	area_space = shm_toc_lookup(toc, PARALLEL_KEY_DSA, false);
 	area = dsa_attach_in_place(area_space, seg);
 
+	/* Give extension chance to retrieve additional context shared by leader node */
+	if (ParallelQueryMain_hook)
+	{
+		(*ParallelQueryMain_hook)(toc);
+	}
+
 	/* Start up the executor */
 	queryDesc->plannedstmt->jitFlags = fpes->jit_flags;
 	ExecutorStart(queryDesc, fpes->eflags);

src/include/access/parallel.h

@@ -81,15 +81,11 @@ extern void ParallelWorkerMain(Datum main_arg);
 /* Below helpers are added to support parallel workers in Babelfish context */
 extern bool IsBabelfishParallelWorker(void);
 
-/* Key for BabelfishFixedParallelState */
-#define BABELFISH_PARALLEL_KEY_FIXED        UINT64CONST(0xBBF0000000000001)
-
 /* Hooks for communicating babelfish related information to parallel worker */
 typedef void (*bbf_InitializeParallelDSM_hook_type)(ParallelContext *pcxt, bool estimate);
 extern PGDLLIMPORT bbf_InitializeParallelDSM_hook_type bbf_InitializeParallelDSM_hook;
 
 typedef void (*bbf_ParallelWorkerMain_hook_type)(shm_toc *toc);
 extern PGDLLIMPORT bbf_ParallelWorkerMain_hook_type bbf_ParallelWorkerMain_hook;
 
-
 #endif							/* PARALLEL_H */

src/include/executor/execParallel.h

@@ -48,4 +48,15 @@ extern void ExecParallelReinitialize(PlanState *planstate,
 
 extern void ParallelQueryMain(dsm_segment *seg, shm_toc *toc);
 
+typedef void (*ParallelQueryMain_hook_type)(shm_toc *toc);
+extern PGDLLIMPORT ParallelQueryMain_hook_type ParallelQueryMain_hook;
+
+/*
+ * When estimate = true passed then caller wants extension to estimate a dynamic shared memory (DSM)
+ * needed by that extension to communicate additional context with Parallel worker.
+ * When estimate = false then caller wants to insert additional context to DSM.
+ */
+typedef void (*ExecInitParallelPlan_hook_type)(EState *estate, ParallelContext *pcxt, bool estimate);
+extern PGDLLIMPORT ExecInitParallelPlan_hook_type ExecInitParallelPlan_hook;
+
 #endif							/* EXECPARALLEL_H */

src/include/executor/executor.h

@@ -111,6 +111,9 @@ extern PGDLLIMPORT ExecUpdateResultTypeTL_hook_type ExecUpdateResultTypeTL_hook;
 typedef bool (*check_rowcount_hook_type) (int es_processed);
 extern PGDLLEXPORT check_rowcount_hook_type check_rowcount_hook;
 
+typedef bool (*ExecCheckOneRelPerms_hook_type) (RTEPermissionInfo *perminfo);
+extern PGDLLEXPORT ExecCheckOneRelPerms_hook_type ExecCheckOneRelPerms_hook;
+
 /*
  * prototypes from functions in execAmi.c
  */
@@ -224,6 +227,8 @@ extern void standard_ExecutorEnd(QueryDesc *queryDesc);
 extern void ExecutorRewind(QueryDesc *queryDesc);
 extern bool ExecCheckPermissions(List *rangeTable,
 								 List *rteperminfos, bool ereport_on_violation);
+/* Wrapper around ExecCheckOneRelPerms */
+extern bool ExecCheckOneRelPerms_wrapper(RTEPermissionInfo *perminfo);
 extern void CheckValidResultRel(ResultRelInfo *resultRelInfo, CmdType operation,
 								List *mergeActions);
 extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,