1 files changed, 53 insertions, 12 deletions

diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 90378474d7d..9869a4dd0e7 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -438,6 +438,7 @@ DefineIndex(Oid relationId,
 			bool skip_build,
 			bool quiet)
 {
+	bool		concurrent;
 	char	   *indexRelationName;
 	char	   *accessMethodName;
 	Oid		   *typeObjectId;
@@ -486,6 +487,18 @@ DefineIndex(Oid relationId,
 	}
 
 	/*
+	 * Force non-concurrent build on temporary relations, even if CONCURRENTLY
+	 * was requested.  Other backends can't access a temporary relation, so
+	 * there's no harm in grabbing a stronger lock, and a non-concurrent DROP
+	 * is more efficient.  Do this before any use of the concurrent option is
+	 * done.
+	 */
+	if (stmt->concurrent && get_rel_persistence(relationId) != RELPERSISTENCE_TEMP)
+		concurrent = true;
+	else
+		concurrent = false;
+
+	/*
 	 * Start progress report.  If we're building a partition, this was already
 	 * done.
 	 */
@@ -494,7 +507,7 @@ DefineIndex(Oid relationId,
 		pgstat_progress_start_command(PROGRESS_COMMAND_CREATE_INDEX,
 									  relationId);
 		pgstat_progress_update_param(PROGRESS_CREATEIDX_COMMAND,
-									 stmt->concurrent ?
+									 concurrent ?
 									 PROGRESS_CREATEIDX_COMMAND_CREATE_CONCURRENTLY :
 									 PROGRESS_CREATEIDX_COMMAND_CREATE);
 	}
@@ -547,7 +560,7 @@ DefineIndex(Oid relationId,
 	 * parallel workers under the control of certain particular ambuild
 	 * functions will need to be updated, too.
 	 */
-	lockmode = stmt->concurrent ? ShareUpdateExclusiveLock : ShareLock;
+	lockmode = concurrent ? ShareUpdateExclusiveLock : ShareLock;
 	rel = table_open(relationId, lockmode);
 
 	namespaceId = RelationGetNamespace(rel);
@@ -590,6 +603,12 @@ DefineIndex(Oid relationId,
 	partitioned = rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE;
 	if (partitioned)
 	{
+		/*
+		 * Note: we check 'stmt->concurrent' rather than 'concurrent', so that
+		 * the error is thrown also for temporary tables.  Seems better to be
+		 * consistent, even though we could do it on temporary table because
+		 * we're not actually doing it concurrently.
+		 */
 		if (stmt->concurrent)
 			ereport(ERROR,
 					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -781,8 +800,8 @@ DefineIndex(Oid relationId,
 							  NIL,	/* expressions, NIL for now */
 							  make_ands_implicit((Expr *) stmt->whereClause),
 							  stmt->unique,
-							  !stmt->concurrent,
-							  stmt->concurrent);
+							  !concurrent,
+							  concurrent);
 
 	typeObjectId = (Oid *) palloc(numberOfAttributes * sizeof(Oid));
 	collationObjectId = (Oid *) palloc(numberOfAttributes * sizeof(Oid));
@@ -944,7 +963,7 @@ DefineIndex(Oid relationId,
 	 * A valid stmt->oldNode implies that we already have a built form of the
 	 * index.  The caller should also decline any index build.
 	 */
-	Assert(!OidIsValid(stmt->oldNode) || (skip_build && !stmt->concurrent));
+	Assert(!OidIsValid(stmt->oldNode) || (skip_build && !concurrent));
 
 	/*
 	 * Make the catalog entries for the index, including constraints. This
@@ -955,11 +974,11 @@ DefineIndex(Oid relationId,
 	flags = constr_flags = 0;
 	if (stmt->isconstraint)
 		flags |= INDEX_CREATE_ADD_CONSTRAINT;
-	if (skip_build || stmt->concurrent || partitioned)
+	if (skip_build || concurrent || partitioned)
 		flags |= INDEX_CREATE_SKIP_BUILD;
 	if (stmt->if_not_exists)
 		flags |= INDEX_CREATE_IF_NOT_EXISTS;
-	if (stmt->concurrent)
+	if (concurrent)
 		flags |= INDEX_CREATE_CONCURRENT;
 	if (partitioned)
 		flags |= INDEX_CREATE_PARTITIONED;
@@ -1256,7 +1275,7 @@ DefineIndex(Oid relationId,
 		return address;
 	}
 
-	if (!stmt->concurrent)
+	if (!concurrent)
 	{
 		/* Close the heap and we're done, in the non-concurrent case */
 		table_close(rel, NoLock);
@@ -2326,6 +2345,11 @@ ReindexIndex(RangeVar *indexRelation, int options, bool concurrent)
 	 * Find and lock index, and check permissions on table; use callback to
 	 * obtain lock on table first, to avoid deadlock hazard.  The lock level
 	 * used here must match the index lock obtained in reindex_index().
+	 *
+	 * If it's a temporary index, we will perform a non-concurrent reindex,
+	 * even if CONCURRENTLY was requested.  In that case, reindex_index() will
+	 * upgrade the lock, but that's OK, because other sessions can't hold
+	 * locks on our temporary table.
 	 */
 	state.concurrent = concurrent;
 	state.locked_table_oid = InvalidOid;
@@ -2350,7 +2374,7 @@ ReindexIndex(RangeVar *indexRelation, int options, bool concurrent)
 	persistence = irel->rd_rel->relpersistence;
 	index_close(irel, NoLock);
 
-	if (concurrent)
+	if (concurrent && persistence != RELPERSISTENCE_TEMP)
 		ReindexRelationConcurrently(indOid, options);
 	else
 		reindex_index(indOid, false, persistence,
@@ -2437,13 +2461,20 @@ ReindexTable(RangeVar *relation, int options, bool concurrent)
 	Oid			heapOid;
 	bool		result;
 
-	/* The lock level used here should match reindex_relation(). */
+	/*
+	 * The lock level used here should match reindex_relation().
+	 *
+	 * If it's a temporary table, we will perform a non-concurrent reindex,
+	 * even if CONCURRENTLY was requested.  In that case, reindex_relation()
+	 * will upgrade the lock, but that's OK, because other sessions can't hold
+	 * locks on our temporary table.
+	 */
 	heapOid = RangeVarGetRelidExtended(relation,
 									   concurrent ? ShareUpdateExclusiveLock : ShareLock,
 									   0,
 									   RangeVarCallbackOwnsTable, NULL);
 
-	if (concurrent)
+	if (concurrent && get_rel_persistence(heapOid) != RELPERSISTENCE_TEMP)
 	{
 		result = ReindexRelationConcurrently(heapOid, options);
 
@@ -2649,7 +2680,7 @@ ReindexMultipleTables(const char *objectName, ReindexObjectType objectKind,
 		/* functions in indexes may want a snapshot set */
 		PushActiveSnapshot(GetTransactionSnapshot());
 
-		if (concurrent)
+		if (concurrent && get_rel_persistence(relid) != RELPERSISTENCE_TEMP)
 		{
 			(void) ReindexRelationConcurrently(relid, options);
 			/* ReindexRelationConcurrently() does the verbose output */
@@ -2697,6 +2728,12 @@ ReindexMultipleTables(const char *objectName, ReindexObjectType objectKind,
  *
  * Returns true if any indexes have been rebuilt (including toast table's
  * indexes, when relevant), otherwise returns false.
+ *
+ * NOTE: This cannot be used on temporary relations.  A concurrent build would
+ * cause issues with ON COMMIT actions triggered by the transactions of the
+ * concurrent build.  Temporary relations are not subject to concurrent
+ * concerns, so there's no need for the more complicated concurrent build,
+ * anyway, and a non-concurrent reindex is more efficient.
  */
 static bool
 ReindexRelationConcurrently(Oid relationOid, int options)
@@ -2940,6 +2977,10 @@ ReindexRelationConcurrently(Oid relationOid, int options)
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
+		/* This function shouldn't be called for temporary relations. */
+		if (indexRel->rd_rel->relpersistence == RELPERSISTENCE_TEMP)
+			elog(ERROR, "cannot reindex a temporary table concurrently");
+
 		pgstat_progress_start_command(PROGRESS_COMMAND_CREATE_INDEX,
 									  RelationGetRelid(heapRel));
 		pgstat_progress_update_param(PROGRESS_CREATEIDX_COMMAND,