Re: Global temporary tables

[Konstantin Knizhnik]

On 13.08.2019 11:27, Craig Ringer wrote:


On Tue, 13 Aug 2019 at 16:19, Konstantin Knizhnik 
<k.knizh...@postgrespro.ru <mailto:k.knizh...@postgrespro.ru>> wrote:



    On 13.08.2019 8:34, Craig Ringer wrote:
    On Tue, 13 Aug 2019 at 00:47, Pavel Stehule
    <pavel.steh...@gmail.com <mailto:pavel.steh...@gmail.com>> wrote:

            But Postgres is not storing this information now anywhere
            else except statistic, isn't it?


        not only - critical numbers are reltuples, relpages from pg_class


    That's a very good point. relallvisible too. How's the global
    temp table impl handling that right now, since you won't be
    changing the pg_class row? AFAICS relpages doesn't need to be up
    to date (and reltuples certainly doesn't) so presumably you're
    just leaving them as zero?
    As far as I understand relpages and reltuples are set only when
    you perform "analyze" of the table.


Also autovacuum's autoanalyze.

When it happen?
I have created normal table, populated it with some data and then wait 
several hours but pg_class was not updated for this table.


I attach to this mail slightly refactored versions of this patches with 
fixes of issues reported in your review.

--
Konstantin Knizhnik
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company

diff --git a/contrib/pg_buffercache/pg_buffercache_pages.c b/contrib/pg_buffercache/pg_buffercache_pages.c
index 1bd579f..2d93f6f 100644
--- a/contrib/pg_buffercache/pg_buffercache_pages.c
+++ b/contrib/pg_buffercache/pg_buffercache_pages.c
@@ -153,9 +153,9 @@ pg_buffercache_pages(PG_FUNCTION_ARGS)
 			buf_state = LockBufHdr(bufHdr);
 
 			fctx->record[i].bufferid = BufferDescriptorGetBuffer(bufHdr);
-			fctx->record[i].relfilenode = bufHdr->tag.rnode.relNode;
-			fctx->record[i].reltablespace = bufHdr->tag.rnode.spcNode;
-			fctx->record[i].reldatabase = bufHdr->tag.rnode.dbNode;
+			fctx->record[i].relfilenode = bufHdr->tag.rnode.node.relNode;
+			fctx->record[i].reltablespace = bufHdr->tag.rnode.node.spcNode;
+			fctx->record[i].reldatabase = bufHdr->tag.rnode.node.dbNode;
 			fctx->record[i].forknum = bufHdr->tag.forkNum;
 			fctx->record[i].blocknum = bufHdr->tag.blockNum;
 			fctx->record[i].usagecount = BUF_STATE_GET_USAGECOUNT(buf_state);
diff --git a/contrib/pg_prewarm/autoprewarm.c b/contrib/pg_prewarm/autoprewarm.c
index 38ae240..8a04954 100644
--- a/contrib/pg_prewarm/autoprewarm.c
+++ b/contrib/pg_prewarm/autoprewarm.c
@@ -608,9 +608,9 @@ apw_dump_now(bool is_bgworker, bool dump_unlogged)
 		if (buf_state & BM_TAG_VALID &&
 			((buf_state & BM_PERMANENT) || dump_unlogged))
 		{
-			block_info_array[num_blocks].database = bufHdr->tag.rnode.dbNode;
-			block_info_array[num_blocks].tablespace = bufHdr->tag.rnode.spcNode;
-			block_info_array[num_blocks].filenode = bufHdr->tag.rnode.relNode;
+			block_info_array[num_blocks].database = bufHdr->tag.rnode.node.dbNode;
+			block_info_array[num_blocks].tablespace = bufHdr->tag.rnode.node.spcNode;
+			block_info_array[num_blocks].filenode = bufHdr->tag.rnode.node.relNode;
 			block_info_array[num_blocks].forknum = bufHdr->tag.forkNum;
 			block_info_array[num_blocks].blocknum = bufHdr->tag.blockNum;
 			++num_blocks;
diff --git a/src/backend/access/gin/ginxlog.c b/src/backend/access/gin/ginxlog.c
index c945b28..14d4e48 100644
--- a/src/backend/access/gin/ginxlog.c
+++ b/src/backend/access/gin/ginxlog.c
@@ -95,13 +95,13 @@ ginRedoInsertEntry(Buffer buffer, bool isLeaf, BlockNumber rightblkno, void *rda
 
 	if (PageAddItem(page, (Item) itup, IndexTupleSize(itup), offset, false, false) == InvalidOffsetNumber)
 	{
-		RelFileNode node;
+		RelFileNodeBackend rnode;
 		ForkNumber	forknum;
 		BlockNumber blknum;
 
-		BufferGetTag(buffer, &node, &forknum, &blknum);
+		BufferGetTag(buffer, &rnode, &forknum, &blknum);
 		elog(ERROR, "failed to add item to index page in %u/%u/%u",
-			 node.spcNode, node.dbNode, node.relNode);
+			 rnode.node.spcNode, rnode.node.dbNode, rnode.node.relNode);
 	}
 }
 
diff --git a/src/backend/access/gist/gistutil.c b/src/backend/access/gist/gistutil.c
index 9726020..c99701d 100644
--- a/src/backend/access/gist/gistutil.c
+++ b/src/backend/access/gist/gistutil.c
@@ -1028,7 +1028,7 @@ gistGetFakeLSN(Relation rel)
 {
 	static XLogRecPtr counter = FirstNormalUnloggedLSN;
 
-	if (rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP)
+	if (RelationHasSessionScope(rel))
 	{
 		/*
 		 * Temporary relations are only accessible in our session, so a simple
diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 09bc6fe..c60effd 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -671,6 +671,7 @@ heapam_relation_copy_data(Relation rel, const RelFileNode *newrnode)
 			 * init fork of an unlogged relation.
 			 */
 			if (rel->rd_rel->relpersistence == RELPERSISTENCE_PERMANENT ||
+				rel->rd_rel->relpersistence == RELPERSISTENCE_SESSION ||
 				(rel->rd_rel->relpersistence == RELPERSISTENCE_UNLOGGED &&
 				 forkNum == INIT_FORKNUM))
 				log_smgrcreate(newrnode, forkNum);
diff --git a/src/backend/access/nbtree/nbtpage.c b/src/backend/access/nbtree/nbtpage.c
index 5962126..bdb6c95 100644
--- a/src/backend/access/nbtree/nbtpage.c
+++ b/src/backend/access/nbtree/nbtpage.c
@@ -763,7 +763,11 @@ _bt_getbuf(Relation rel, BlockNumber blkno, int access)
 		/* Read an existing block of the relation */
 		buf = ReadBuffer(rel, blkno);
 		LockBuffer(buf, access);
-		_bt_checkpage(rel, buf);
+		/* Session temporary relation may be not yet initialized for this backend. */
+		if (blkno == BTREE_METAPAGE && GlobalTempRelationPageIsNotInitialized(rel, BufferGetPage(buf)))
+			_bt_initmetapage(BufferGetPage(buf), P_NONE, 0);
+		else
+			_bt_checkpage(rel, buf);
 	}
 	else
 	{
diff --git a/src/backend/access/transam/xloginsert.c b/src/backend/access/transam/xloginsert.c
index 3ec67d4..edec8ca 100644
--- a/src/backend/access/transam/xloginsert.c
+++ b/src/backend/access/transam/xloginsert.c
@@ -213,6 +213,7 @@ void
 XLogRegisterBuffer(uint8 block_id, Buffer buffer, uint8 flags)
 {
 	registered_buffer *regbuf;
+	RelFileNodeBackend rnode;
 
 	/* NO_IMAGE doesn't make sense with FORCE_IMAGE */
 	Assert(!((flags & REGBUF_FORCE_IMAGE) && (flags & (REGBUF_NO_IMAGE))));
@@ -227,7 +228,8 @@ XLogRegisterBuffer(uint8 block_id, Buffer buffer, uint8 flags)
 
 	regbuf = &registered_buffers[block_id];
 
-	BufferGetTag(buffer, &regbuf->rnode, &regbuf->forkno, &regbuf->block);
+	BufferGetTag(buffer, &rnode, &regbuf->forkno, &regbuf->block);
+	regbuf->rnode = rnode.node;
 	regbuf->page = BufferGetPage(buffer);
 	regbuf->flags = flags;
 	regbuf->rdata_tail = (XLogRecData *) &regbuf->rdata_head;
@@ -919,7 +921,7 @@ XLogSaveBufferForHint(Buffer buffer, bool buffer_std)
 		int			flags;
 		PGAlignedBlock copied_buffer;
 		char	   *origdata = (char *) BufferGetBlock(buffer);
-		RelFileNode rnode;
+		RelFileNodeBackend rnode;
 		ForkNumber	forkno;
 		BlockNumber blkno;
 
@@ -948,7 +950,7 @@ XLogSaveBufferForHint(Buffer buffer, bool buffer_std)
 			flags |= REGBUF_STANDARD;
 
 		BufferGetTag(buffer, &rnode, &forkno, &blkno);
-		XLogRegisterBlock(0, &rnode, forkno, blkno, copied_buffer.data, flags);
+		XLogRegisterBlock(0, &rnode.node, forkno, blkno, copied_buffer.data, flags);
 
 		recptr = XLogInsert(RM_XLOG_ID, XLOG_FPI_FOR_HINT);
 	}
@@ -1009,7 +1011,7 @@ XLogRecPtr
 log_newpage_buffer(Buffer buffer, bool page_std)
 {
 	Page		page = BufferGetPage(buffer);
-	RelFileNode rnode;
+	RelFileNodeBackend rnode;
 	ForkNumber	forkNum;
 	BlockNumber blkno;
 
@@ -1018,7 +1020,7 @@ log_newpage_buffer(Buffer buffer, bool page_std)
 
 	BufferGetTag(buffer, &rnode, &forkNum, &blkno);
 
-	return log_newpage(&rnode, forkNum, blkno, page, page_std);
+	return log_newpage(&rnode.node, forkNum, blkno, page, page_std);
 }
 
 /*
diff --git a/src/backend/catalog/catalog.c b/src/backend/catalog/catalog.c
index a065419..8814afb 100644
--- a/src/backend/catalog/catalog.c
+++ b/src/backend/catalog/catalog.c
@@ -409,6 +409,9 @@ GetNewRelFileNode(Oid reltablespace, Relation pg_class, char relpersistence)
 		case RELPERSISTENCE_TEMP:
 			backend = BackendIdForTempRelations();
 			break;
+		case RELPERSISTENCE_SESSION:
+			backend = BackendIdForSessionRelations();
+			break;
 		case RELPERSISTENCE_UNLOGGED:
 		case RELPERSISTENCE_PERMANENT:
 			backend = InvalidBackendId;
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 99ae159..24b2438 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -3612,7 +3612,7 @@ reindex_relation(Oid relid, int flags, int options)
 		if (flags & REINDEX_REL_FORCE_INDEXES_UNLOGGED)
 			persistence = RELPERSISTENCE_UNLOGGED;
 		else if (flags & REINDEX_REL_FORCE_INDEXES_PERMANENT)
-			persistence = RELPERSISTENCE_PERMANENT;
+			persistence = rel->rd_rel->relpersistence == RELPERSISTENCE_SESSION ? RELPERSISTENCE_SESSION : RELPERSISTENCE_PERMANENT;
 		else
 			persistence = rel->rd_rel->relpersistence;
 
diff --git a/src/backend/catalog/storage.c b/src/backend/catalog/storage.c
index 3cc886f..a111ddc 100644
--- a/src/backend/catalog/storage.c
+++ b/src/backend/catalog/storage.c
@@ -93,6 +93,10 @@ RelationCreateStorage(RelFileNode rnode, char relpersistence)
 			backend = InvalidBackendId;
 			needs_wal = false;
 			break;
+		case RELPERSISTENCE_SESSION:
+			backend = BackendIdForSessionRelations();
+			needs_wal = false;
+			break;
 		case RELPERSISTENCE_PERMANENT:
 			backend = InvalidBackendId;
 			needs_wal = true;
diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c
index cedb4ee..d11c5b3 100644
--- a/src/backend/commands/cluster.c
+++ b/src/backend/commands/cluster.c
@@ -1400,7 +1400,7 @@ finish_heap_swap(Oid OIDOldHeap, Oid OIDNewHeap,
 	 */
 	if (newrelpersistence == RELPERSISTENCE_UNLOGGED)
 		reindex_flags |= REINDEX_REL_FORCE_INDEXES_UNLOGGED;
-	else if (newrelpersistence == RELPERSISTENCE_PERMANENT)
+	else if (newrelpersistence != RELPERSISTENCE_TEMP)
 		reindex_flags |= REINDEX_REL_FORCE_INDEXES_PERMANENT;
 
 	/* Report that we are now reindexing relations */
diff --git a/src/backend/commands/sequence.c b/src/backend/commands/sequence.c
index 0960b33..6c3998f 100644
--- a/src/backend/commands/sequence.c
+++ b/src/backend/commands/sequence.c
@@ -94,7 +94,7 @@ static HTAB *seqhashtab = NULL; /* hash table for SeqTable items */
  */
 static SeqTableData *last_used_seq = NULL;
 
-static void fill_seq_with_data(Relation rel, HeapTuple tuple);
+static void fill_seq_with_data(Relation rel, HeapTuple tuple, Buffer buf);
 static Relation lock_and_open_sequence(SeqTable seq);
 static void create_seq_hashtable(void);
 static void init_sequence(Oid relid, SeqTable *p_elm, Relation *p_rel);
@@ -222,7 +222,7 @@ DefineSequence(ParseState *pstate, CreateSeqStmt *seq)
 
 	/* now initialize the sequence's data */
 	tuple = heap_form_tuple(tupDesc, value, null);
-	fill_seq_with_data(rel, tuple);
+	fill_seq_with_data(rel, tuple, InvalidBuffer);
 
 	/* process OWNED BY if given */
 	if (owned_by)
@@ -327,7 +327,7 @@ ResetSequence(Oid seq_relid)
 	/*
 	 * Insert the modified tuple into the new storage file.
 	 */
-	fill_seq_with_data(seq_rel, tuple);
+	fill_seq_with_data(seq_rel, tuple, InvalidBuffer);
 
 	/* Clear local cache so that we don't think we have cached numbers */
 	/* Note that we do not change the currval() state */
@@ -340,18 +340,21 @@ ResetSequence(Oid seq_relid)
  * Initialize a sequence's relation with the specified tuple as content
  */
 static void
-fill_seq_with_data(Relation rel, HeapTuple tuple)
+fill_seq_with_data(Relation rel, HeapTuple tuple, Buffer buf)
 {
-	Buffer		buf;
 	Page		page;
 	sequence_magic *sm;
 	OffsetNumber offnum;
+	bool lockBuffer = false;
 
 	/* Initialize first page of relation with special magic number */
 
-	buf = ReadBuffer(rel, P_NEW);
-	Assert(BufferGetBlockNumber(buf) == 0);
-
+	if (buf == InvalidBuffer)
+	{
+		buf = ReadBuffer(rel, P_NEW);
+		Assert(BufferGetBlockNumber(buf) == 0);
+		lockBuffer = true;
+	}
 	page = BufferGetPage(buf);
 
 	PageInit(page, BufferGetPageSize(buf), sizeof(sequence_magic));
@@ -360,7 +363,8 @@ fill_seq_with_data(Relation rel, HeapTuple tuple)
 
 	/* Now insert sequence tuple */
 
-	LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
+	if (lockBuffer)
+		LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
 
 	/*
 	 * Since VACUUM does not process sequences, we have to force the tuple to
@@ -410,7 +414,8 @@ fill_seq_with_data(Relation rel, HeapTuple tuple)
 
 	END_CRIT_SECTION();
 
-	UnlockReleaseBuffer(buf);
+	if (lockBuffer)
+		UnlockReleaseBuffer(buf);
 }
 
 /*
@@ -502,7 +507,7 @@ AlterSequence(ParseState *pstate, AlterSeqStmt *stmt)
 		/*
 		 * Insert the modified tuple into the new storage file.
 		 */
-		fill_seq_with_data(seqrel, newdatatuple);
+		fill_seq_with_data(seqrel, newdatatuple, InvalidBuffer);
 	}
 
 	/* process OWNED BY if given */
@@ -1178,6 +1183,17 @@ read_seq_tuple(Relation rel, Buffer *buf, HeapTuple seqdatatuple)
 	LockBuffer(*buf, BUFFER_LOCK_EXCLUSIVE);
 
 	page = BufferGetPage(*buf);
+	if (GlobalTempRelationPageIsNotInitialized(rel, page))
+	{
+		/* Initialize sequence for global temporary tables */
+		Datum		value[SEQ_COL_LASTCOL] = {0};
+		bool		null[SEQ_COL_LASTCOL] = {false};
+		HeapTuple tuple;
+		value[SEQ_COL_LASTVAL-1] = Int64GetDatumFast(1); /* start sequence with 1 */
+		tuple = heap_form_tuple(RelationGetDescr(rel), value, null);
+		fill_seq_with_data(rel, tuple, *buf);
+	}
+
 	sm = (sequence_magic *) PageGetSpecialPointer(page);
 
 	if (sm->magic != SEQ_MAGIC)
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index fb2be10..a31f775 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -586,7 +586,7 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
 	 * Check consistency of arguments
 	 */
 	if (stmt->oncommit != ONCOMMIT_NOOP
-		&& stmt->relation->relpersistence != RELPERSISTENCE_TEMP)
+		&& !IsLocalRelpersistence(stmt->relation->relpersistence))
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
 				 errmsg("ON COMMIT can only be used on temporary tables")));
@@ -1772,7 +1772,8 @@ ExecuteTruncateGuts(List *explicit_rels, List *relids, List *relids_logged,
 		 * table or the current physical file to be thrown away anyway.
 		 */
 		if (rel->rd_createSubid == mySubid ||
-			rel->rd_newRelfilenodeSubid == mySubid)
+			rel->rd_newRelfilenodeSubid == mySubid ||
+			rel->rd_rel->relpersistence == RELPERSISTENCE_SESSION)
 		{
 			/* Immediate, non-rollbackable truncation is OK */
 			heap_truncate_one_rel(rel);
@@ -7678,6 +7679,12 @@ ATAddForeignKeyConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
 						(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
 						 errmsg("constraints on unlogged tables may reference only permanent or unlogged tables")));
 			break;
+		case RELPERSISTENCE_SESSION:
+			if (pkrel->rd_rel->relpersistence != RELPERSISTENCE_SESSION)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+						 errmsg("constraints on session tables may reference only session tables")));
+			break;
 		case RELPERSISTENCE_TEMP:
 			if (pkrel->rd_rel->relpersistence != RELPERSISTENCE_TEMP)
 				ereport(ERROR,
@@ -14082,6 +14089,13 @@ ATPrepChangePersistence(Relation rel, bool toLogged)
 							RelationGetRelationName(rel)),
 					 errtable(rel)));
 			break;
+		case RELPERSISTENCE_SESSION:
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+					 errmsg("cannot change logged status of session table \"%s\"",
+							RelationGetRelationName(rel)),
+					 errtable(rel)));
+			break;
 		case RELPERSISTENCE_PERMANENT:
 			if (toLogged)
 				/* nothing to do */
@@ -14569,14 +14583,7 @@ PreCommit_on_commit_actions(void)
 				/* Do nothing (there shouldn't be such entries, actually) */
 				break;
 			case ONCOMMIT_DELETE_ROWS:
-
-				/*
-				 * If this transaction hasn't accessed any temporary
-				 * relations, we can skip truncating ON COMMIT DELETE ROWS
-				 * tables, as they must still be empty.
-				 */
-				if ((MyXactFlags & XACT_FLAGS_ACCESSEDTEMPNAMESPACE))
-					oids_to_truncate = lappend_oid(oids_to_truncate, oc->relid);
+				oids_to_truncate = lappend_oid(oids_to_truncate, oc->relid);
 				break;
 			case ONCOMMIT_DROP:
 				oids_to_drop = lappend_oid(oids_to_drop, oc->relid);
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index c97bb36..f9b2000 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -3265,20 +3265,11 @@ OptTemp:	TEMPORARY					{ $$ = RELPERSISTENCE_TEMP; }
 			| TEMP						{ $$ = RELPERSISTENCE_TEMP; }
 			| LOCAL TEMPORARY			{ $$ = RELPERSISTENCE_TEMP; }
 			| LOCAL TEMP				{ $$ = RELPERSISTENCE_TEMP; }
-			| GLOBAL TEMPORARY
-				{
-					ereport(WARNING,
-							(errmsg("GLOBAL is deprecated in temporary table creation"),
-							 parser_errposition(@1)));
-					$$ = RELPERSISTENCE_TEMP;
-				}
-			| GLOBAL TEMP
-				{
-					ereport(WARNING,
-							(errmsg("GLOBAL is deprecated in temporary table creation"),
-							 parser_errposition(@1)));
-					$$ = RELPERSISTENCE_TEMP;
-				}
+			| GLOBAL TEMPORARY          { $$ = RELPERSISTENCE_SESSION; }
+			| GLOBAL TEMP               { $$ = RELPERSISTENCE_SESSION; }
+			| SESSION                   { $$ = RELPERSISTENCE_SESSION; }
+			| SESSION TEMPORARY         { $$ = RELPERSISTENCE_SESSION; }
+			| SESSION TEMP              { $$ = RELPERSISTENCE_SESSION; }
 			| UNLOGGED					{ $$ = RELPERSISTENCE_UNLOGGED; }
 			| /*EMPTY*/					{ $$ = RELPERSISTENCE_PERMANENT; }
 		;
diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c
index a9b2f8b..2f261b9 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -437,6 +437,14 @@ generateSerialExtraStmts(CreateStmtContext *cxt, ColumnDef *column,
 	seqstmt->options = seqoptions;
 
 	/*
+	 * Why we should not always use persistence of parent table?
+	 * Although it is prohibited to have unlogged sequences,
+	 * unlogged tables with SERIAL fields are accepted!
+	 */
+	if (cxt->relation->relpersistence != RELPERSISTENCE_UNLOGGED)
+		seqstmt->sequence->relpersistence = cxt->relation->relpersistence;
+
+	/*
 	 * If a sequence data type was specified, add it to the options.  Prepend
 	 * to the list rather than append; in case a user supplied their own AS
 	 * clause, the "redundant options" error will point to their occurrence,
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index 073f313..3383c35 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -2069,7 +2069,7 @@ do_autovacuum(void)
 		 * Check if it is a temp table (presumably, of some other backend's).
 		 * We cannot safely process other backends' temp tables.
 		 */
-		if (classForm->relpersistence == RELPERSISTENCE_TEMP)
+		if (IsLocalRelpersistence(classForm->relpersistence))
 		{
 			/*
 			 * We just ignore it if the owning backend is still active and
@@ -2154,7 +2154,7 @@ do_autovacuum(void)
 		/*
 		 * We cannot safely process other backends' temp tables, so skip 'em.
 		 */
-		if (classForm->relpersistence == RELPERSISTENCE_TEMP)
+		if (IsLocalRelpersistence(classForm->relpersistence))
 			continue;
 
 		relid = classForm->oid;
diff --git a/src/backend/replication/logical/reorderbuffer.c b/src/backend/replication/logical/reorderbuffer.c
index e8ffa04..2004d2f 100644
--- a/src/backend/replication/logical/reorderbuffer.c
+++ b/src/backend/replication/logical/reorderbuffer.c
@@ -3483,6 +3483,7 @@ ResolveCminCmaxDuringDecoding(HTAB *tuplecid_data,
 {
 	ReorderBufferTupleCidKey key;
 	ReorderBufferTupleCidEnt *ent;
+	RelFileNodeBackend rnode;
 	ForkNumber	forkno;
 	BlockNumber blockno;
 	bool		updated_mapping = false;
@@ -3496,7 +3497,8 @@ ResolveCminCmaxDuringDecoding(HTAB *tuplecid_data,
 	 * get relfilenode from the buffer, no convenient way to access it other
 	 * than that.
 	 */
-	BufferGetTag(buffer, &key.relnode, &forkno, &blockno);
+	BufferGetTag(buffer, &rnode, &forkno, &blockno);
+	key.relnode = rnode.node;
 
 	/* tuples can only be in the main fork */
 	Assert(forkno == MAIN_FORKNUM);
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index 6f3a402..76ce953 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -556,7 +556,7 @@ PrefetchBuffer(Relation reln, ForkNumber forkNum, BlockNumber blockNum)
 		int			buf_id;
 
 		/* create a tag so we can lookup the buffer */
-		INIT_BUFFERTAG(newTag, reln->rd_smgr->smgr_rnode.node,
+		INIT_BUFFERTAG(newTag, reln->rd_smgr->smgr_rnode,
 					   forkNum, blockNum);
 
 		/* determine its hash code and partition lock ID */
@@ -710,7 +710,7 @@ ReadBuffer_common(SMgrRelation smgr, char relpersistence, ForkNumber forkNum,
 	Block		bufBlock;
 	bool		found;
 	bool		isExtend;
-	bool		isLocalBuf = SmgrIsTemp(smgr);
+	bool		isLocalBuf = SmgrIsTemp(smgr) && relpersistence == RELPERSISTENCE_TEMP;
 
 	*hit = false;
 
@@ -1010,7 +1010,7 @@ BufferAlloc(SMgrRelation smgr, char relpersistence, ForkNumber forkNum,
 	uint32		buf_state;
 
 	/* create a tag so we can lookup the buffer */
-	INIT_BUFFERTAG(newTag, smgr->smgr_rnode.node, forkNum, blockNum);
+	INIT_BUFFERTAG(newTag, smgr->smgr_rnode, forkNum, blockNum);
 
 	/* determine its hash code and partition lock ID */
 	newHash = BufTableHashCode(&newTag);
@@ -1532,7 +1532,8 @@ ReleaseAndReadBuffer(Buffer buffer,
 		{
 			bufHdr = GetLocalBufferDescriptor(-buffer - 1);
 			if (bufHdr->tag.blockNum == blockNum &&
-				RelFileNodeEquals(bufHdr->tag.rnode, relation->rd_node) &&
+				RelFileNodeEquals(bufHdr->tag.rnode.node, relation->rd_node) &&
+				bufHdr->tag.rnode.backend == relation->rd_backend &&
 				bufHdr->tag.forkNum == forkNum)
 				return buffer;
 			ResourceOwnerForgetBuffer(CurrentResourceOwner, buffer);
@@ -1543,7 +1544,8 @@ ReleaseAndReadBuffer(Buffer buffer,
 			bufHdr = GetBufferDescriptor(buffer - 1);
 			/* we have pin, so it's ok to examine tag without spinlock */
 			if (bufHdr->tag.blockNum == blockNum &&
-				RelFileNodeEquals(bufHdr->tag.rnode, relation->rd_node) &&
+				RelFileNodeEquals(bufHdr->tag.rnode.node, relation->rd_node) &&
+				bufHdr->tag.rnode.backend == relation->rd_backend &&
 				bufHdr->tag.forkNum == forkNum)
 				return buffer;
 			UnpinBuffer(bufHdr, true);
@@ -1845,8 +1847,8 @@ BufferSync(int flags)
 
 			item = &CkptBufferIds[num_to_scan++];
 			item->buf_id = buf_id;
-			item->tsId = bufHdr->tag.rnode.spcNode;
-			item->relNode = bufHdr->tag.rnode.relNode;
+			item->tsId = bufHdr->tag.rnode.node.spcNode;
+			item->relNode = bufHdr->tag.rnode.node.relNode;
 			item->forkNum = bufHdr->tag.forkNum;
 			item->blockNum = bufHdr->tag.blockNum;
 		}
@@ -2559,7 +2561,7 @@ PrintBufferLeakWarning(Buffer buffer)
 	}
 
 	/* theoretically we should lock the bufhdr here */
-	path = relpathbackend(buf->tag.rnode, backend, buf->tag.forkNum);
+	path = relpathbackend(buf->tag.rnode.node, backend, buf->tag.forkNum);
 	buf_state = pg_atomic_read_u32(&buf->state);
 	elog(WARNING,
 		 "buffer refcount leak: [%03d] "
@@ -2631,7 +2633,7 @@ BufferGetBlockNumber(Buffer buffer)
  *		a buffer.
  */
 void
-BufferGetTag(Buffer buffer, RelFileNode *rnode, ForkNumber *forknum,
+BufferGetTag(Buffer buffer, RelFileNodeBackend *rnode, ForkNumber *forknum,
 			 BlockNumber *blknum)
 {
 	BufferDesc *bufHdr;
@@ -2696,7 +2698,7 @@ FlushBuffer(BufferDesc *buf, SMgrRelation reln)
 
 	/* Find smgr relation for buffer */
 	if (reln == NULL)
-		reln = smgropen(buf->tag.rnode, InvalidBackendId);
+		reln = smgropen(buf->tag.rnode.node, buf->tag.rnode.backend);
 
 	TRACE_POSTGRESQL_BUFFER_FLUSH_START(buf->tag.forkNum,
 										buf->tag.blockNum,
@@ -2930,7 +2932,7 @@ DropRelFileNodeBuffers(RelFileNodeBackend rnode, ForkNumber forkNum,
 	int			i;
 
 	/* If it's a local relation, it's localbuf.c's problem. */
-	if (RelFileNodeBackendIsTemp(rnode))
+	if (RelFileNodeBackendIsLocalTemp(rnode))
 	{
 		if (rnode.backend == MyBackendId)
 			DropRelFileNodeLocalBuffers(rnode.node, forkNum, firstDelBlock);
@@ -2958,11 +2960,11 @@ DropRelFileNodeBuffers(RelFileNodeBackend rnode, ForkNumber forkNum,
 		 * We could check forkNum and blockNum as well as the rnode, but the
 		 * incremental win from doing so seems small.
 		 */
-		if (!RelFileNodeEquals(bufHdr->tag.rnode, rnode.node))
+		if (!RelFileNodeBackendEquals(bufHdr->tag.rnode, rnode))
 			continue;
 
 		buf_state = LockBufHdr(bufHdr);
-		if (RelFileNodeEquals(bufHdr->tag.rnode, rnode.node) &&
+		if (RelFileNodeBackendEquals(bufHdr->tag.rnode, rnode) &&
 			bufHdr->tag.forkNum == forkNum &&
 			bufHdr->tag.blockNum >= firstDelBlock)
 			InvalidateBuffer(bufHdr);	/* releases spinlock */
@@ -2985,24 +2987,24 @@ DropRelFileNodesAllBuffers(RelFileNodeBackend *rnodes, int nnodes)
 {
 	int			i,
 				n = 0;
-	RelFileNode *nodes;
+	RelFileNodeBackend *nodes;
 	bool		use_bsearch;
 
 	if (nnodes == 0)
 		return;
 
-	nodes = palloc(sizeof(RelFileNode) * nnodes);	/* non-local relations */
+	nodes = palloc(sizeof(RelFileNodeBackend) * nnodes);	/* non-local relations */
 
 	/* If it's a local relation, it's localbuf.c's problem. */
 	for (i = 0; i < nnodes; i++)
 	{
-		if (RelFileNodeBackendIsTemp(rnodes[i]))
+		if (RelFileNodeBackendIsLocalTemp(rnodes[i]))
 		{
 			if (rnodes[i].backend == MyBackendId)
 				DropRelFileNodeAllLocalBuffers(rnodes[i].node);
 		}
 		else
-			nodes[n++] = rnodes[i].node;
+			nodes[n++] = rnodes[i];
 	}
 
 	/*
@@ -3025,11 +3027,11 @@ DropRelFileNodesAllBuffers(RelFileNodeBackend *rnodes, int nnodes)
 
 	/* sort the list of rnodes if necessary */
 	if (use_bsearch)
-		pg_qsort(nodes, n, sizeof(RelFileNode), rnode_comparator);
+		pg_qsort(nodes, n, sizeof(RelFileNodeBackend), rnode_comparator);
 
 	for (i = 0; i < NBuffers; i++)
 	{
-		RelFileNode *rnode = NULL;
+		RelFileNodeBackend *rnode = NULL;
 		BufferDesc *bufHdr = GetBufferDescriptor(i);
 		uint32		buf_state;
 
@@ -3044,7 +3046,7 @@ DropRelFileNodesAllBuffers(RelFileNodeBackend *rnodes, int nnodes)
 
 			for (j = 0; j < n; j++)
 			{
-				if (RelFileNodeEquals(bufHdr->tag.rnode, nodes[j]))
+				if (RelFileNodeBackendEquals(bufHdr->tag.rnode, nodes[j]))
 				{
 					rnode = &nodes[j];
 					break;
@@ -3054,7 +3056,7 @@ DropRelFileNodesAllBuffers(RelFileNodeBackend *rnodes, int nnodes)
 		else
 		{
 			rnode = bsearch((const void *) &(bufHdr->tag.rnode),
-							nodes, n, sizeof(RelFileNode),
+							nodes, n, sizeof(RelFileNodeBackend),
 							rnode_comparator);
 		}
 
@@ -3063,7 +3065,7 @@ DropRelFileNodesAllBuffers(RelFileNodeBackend *rnodes, int nnodes)
 			continue;
 
 		buf_state = LockBufHdr(bufHdr);
-		if (RelFileNodeEquals(bufHdr->tag.rnode, (*rnode)))
+		if (RelFileNodeBackendEquals(bufHdr->tag.rnode, (*rnode)))
 			InvalidateBuffer(bufHdr);	/* releases spinlock */
 		else
 			UnlockBufHdr(bufHdr, buf_state);
@@ -3102,11 +3104,11 @@ DropDatabaseBuffers(Oid dbid)
 		 * As in DropRelFileNodeBuffers, an unlocked precheck should be safe
 		 * and saves some cycles.
 		 */
-		if (bufHdr->tag.rnode.dbNode != dbid)
+		if (bufHdr->tag.rnode.node.dbNode != dbid)
 			continue;
 
 		buf_state = LockBufHdr(bufHdr);
-		if (bufHdr->tag.rnode.dbNode == dbid)
+		if (bufHdr->tag.rnode.node.dbNode == dbid)
 			InvalidateBuffer(bufHdr);	/* releases spinlock */
 		else
 			UnlockBufHdr(bufHdr, buf_state);
@@ -3136,7 +3138,7 @@ PrintBufferDescs(void)
 			 "[%02d] (freeNext=%d, rel=%s, "
 			 "blockNum=%u, flags=0x%x, refcount=%u %d)",
 			 i, buf->freeNext,
-			 relpathbackend(buf->tag.rnode, InvalidBackendId, buf->tag.forkNum),
+			 relpath(buf->tag.rnode, buf->tag.forkNum),
 			 buf->tag.blockNum, buf->flags,
 			 buf->refcount, GetPrivateRefCount(b));
 	}
@@ -3204,7 +3206,8 @@ FlushRelationBuffers(Relation rel)
 			uint32		buf_state;
 
 			bufHdr = GetLocalBufferDescriptor(i);
-			if (RelFileNodeEquals(bufHdr->tag.rnode, rel->rd_node) &&
+			if (RelFileNodeEquals(bufHdr->tag.rnode.node, rel->rd_node) &&
+				bufHdr->tag.rnode.backend == rel->rd_backend &&
 				((buf_state = pg_atomic_read_u32(&bufHdr->state)) &
 				 (BM_VALID | BM_DIRTY)) == (BM_VALID | BM_DIRTY))
 			{
@@ -3251,13 +3254,15 @@ FlushRelationBuffers(Relation rel)
 		 * As in DropRelFileNodeBuffers, an unlocked precheck should be safe
 		 * and saves some cycles.
 		 */
-		if (!RelFileNodeEquals(bufHdr->tag.rnode, rel->rd_node))
+		if (!RelFileNodeEquals(bufHdr->tag.rnode.node, rel->rd_node)
+			|| bufHdr->tag.rnode.backend != rel->rd_backend)
 			continue;
 
 		ReservePrivateRefCountEntry();
 
 		buf_state = LockBufHdr(bufHdr);
-		if (RelFileNodeEquals(bufHdr->tag.rnode, rel->rd_node) &&
+		if (RelFileNodeEquals(bufHdr->tag.rnode.node, rel->rd_node) &&
+			bufHdr->tag.rnode.backend == rel->rd_backend &&
 			(buf_state & (BM_VALID | BM_DIRTY)) == (BM_VALID | BM_DIRTY))
 		{
 			PinBuffer_Locked(bufHdr);
@@ -3305,13 +3310,13 @@ FlushDatabaseBuffers(Oid dbid)
 		 * As in DropRelFileNodeBuffers, an unlocked precheck should be safe
 		 * and saves some cycles.
 		 */
-		if (bufHdr->tag.rnode.dbNode != dbid)
+		if (bufHdr->tag.rnode.node.dbNode != dbid)
 			continue;
 
 		ReservePrivateRefCountEntry();
 
 		buf_state = LockBufHdr(bufHdr);
-		if (bufHdr->tag.rnode.dbNode == dbid &&
+		if (bufHdr->tag.rnode.node.dbNode == dbid &&
 			(buf_state & (BM_VALID | BM_DIRTY)) == (BM_VALID | BM_DIRTY))
 		{
 			PinBuffer_Locked(bufHdr);
@@ -4051,7 +4056,7 @@ AbortBufferIO(void)
 				/* Buffer is pinned, so we can read tag without spinlock */
 				char	   *path;
 
-				path = relpathperm(buf->tag.rnode, buf->tag.forkNum);
+				path = relpath(buf->tag.rnode, buf->tag.forkNum);
 				ereport(WARNING,
 						(errcode(ERRCODE_IO_ERROR),
 						 errmsg("could not write block %u of %s",
@@ -4075,7 +4080,7 @@ shared_buffer_write_error_callback(void *arg)
 	/* Buffer is pinned, so we can read the tag without locking the spinlock */
 	if (bufHdr != NULL)
 	{
-		char	   *path = relpathperm(bufHdr->tag.rnode, bufHdr->tag.forkNum);
+		char	   *path = relpath(bufHdr->tag.rnode, bufHdr->tag.forkNum);
 
 		errcontext("writing block %u of relation %s",
 				   bufHdr->tag.blockNum, path);
@@ -4093,7 +4098,7 @@ local_buffer_write_error_callback(void *arg)
 
 	if (bufHdr != NULL)
 	{
-		char	   *path = relpathbackend(bufHdr->tag.rnode, MyBackendId,
+		char	   *path = relpathbackend(bufHdr->tag.rnode.node, MyBackendId,
 										  bufHdr->tag.forkNum);
 
 		errcontext("writing block %u of relation %s",
@@ -4108,22 +4113,27 @@ local_buffer_write_error_callback(void *arg)
 static int
 rnode_comparator(const void *p1, const void *p2)
 {
-	RelFileNode n1 = *(const RelFileNode *) p1;
-	RelFileNode n2 = *(const RelFileNode *) p2;
+	RelFileNodeBackend n1 = *(const RelFileNodeBackend *) p1;
+	RelFileNodeBackend n2 = *(const RelFileNodeBackend *) p2;
 
-	if (n1.relNode < n2.relNode)
+	if (n1.node.relNode < n2.node.relNode)
 		return -1;
-	else if (n1.relNode > n2.relNode)
+	else if (n1.node.relNode > n2.node.relNode)
 		return 1;
 
-	if (n1.dbNode < n2.dbNode)
+	if (n1.node.dbNode < n2.node.dbNode)
 		return -1;
-	else if (n1.dbNode > n2.dbNode)
+	else if (n1.node.dbNode > n2.node.dbNode)
 		return 1;
 
-	if (n1.spcNode < n2.spcNode)
+	if (n1.node.spcNode < n2.node.spcNode)
 		return -1;
-	else if (n1.spcNode > n2.spcNode)
+	else if (n1.node.spcNode > n2.node.spcNode)
+		return 1;
+
+	if (n1.backend < n2.backend)
+		return -1;
+	else if (n1.backend > n2.backend)
 		return 1;
 	else
 		return 0;
@@ -4359,7 +4369,7 @@ IssuePendingWritebacks(WritebackContext *context)
 			next = &context->pending_writebacks[i + ahead + 1];
 
 			/* different file, stop */
-			if (!RelFileNodeEquals(cur->tag.rnode, next->tag.rnode) ||
+			if (!RelFileNodeBackendEquals(cur->tag.rnode, next->tag.rnode) ||
 				cur->tag.forkNum != next->tag.forkNum)
 				break;
 
@@ -4378,7 +4388,7 @@ IssuePendingWritebacks(WritebackContext *context)
 		i += ahead;
 
 		/* and finally tell the kernel to write the data to storage */
-		reln = smgropen(tag.rnode, InvalidBackendId);
+		reln = smgropen(tag.rnode.node, tag.rnode.backend);
 		smgrwriteback(reln, tag.forkNum, tag.blockNum, nblocks);
 	}
 
diff --git a/src/backend/storage/buffer/localbuf.c b/src/backend/storage/buffer/localbuf.c
index f5f6a29..6bd5ecb 100644
--- a/src/backend/storage/buffer/localbuf.c
+++ b/src/backend/storage/buffer/localbuf.c
@@ -68,7 +68,7 @@ LocalPrefetchBuffer(SMgrRelation smgr, ForkNumber forkNum,
 	BufferTag	newTag;			/* identity of requested block */
 	LocalBufferLookupEnt *hresult;
 
-	INIT_BUFFERTAG(newTag, smgr->smgr_rnode.node, forkNum, blockNum);
+	INIT_BUFFERTAG(newTag, smgr->smgr_rnode, forkNum, blockNum);
 
 	/* Initialize local buffers if first request in this session */
 	if (LocalBufHash == NULL)
@@ -111,7 +111,7 @@ LocalBufferAlloc(SMgrRelation smgr, ForkNumber forkNum, BlockNumber blockNum,
 	bool		found;
 	uint32		buf_state;
 
-	INIT_BUFFERTAG(newTag, smgr->smgr_rnode.node, forkNum, blockNum);
+	INIT_BUFFERTAG(newTag, smgr->smgr_rnode, forkNum, blockNum);
 
 	/* Initialize local buffers if first request in this session */
 	if (LocalBufHash == NULL)
@@ -209,7 +209,7 @@ LocalBufferAlloc(SMgrRelation smgr, ForkNumber forkNum, BlockNumber blockNum,
 		Page		localpage = (char *) LocalBufHdrGetBlock(bufHdr);
 
 		/* Find smgr relation for buffer */
-		oreln = smgropen(bufHdr->tag.rnode, MyBackendId);
+		oreln = smgropen(bufHdr->tag.rnode.node, MyBackendId);
 
 		PageSetChecksumInplace(localpage, bufHdr->tag.blockNum);
 
@@ -331,14 +331,14 @@ DropRelFileNodeLocalBuffers(RelFileNode rnode, ForkNumber forkNum,
 		buf_state = pg_atomic_read_u32(&bufHdr->state);
 
 		if ((buf_state & BM_TAG_VALID) &&
-			RelFileNodeEquals(bufHdr->tag.rnode, rnode) &&
+			RelFileNodeEquals(bufHdr->tag.rnode.node, rnode) &&
 			bufHdr->tag.forkNum == forkNum &&
 			bufHdr->tag.blockNum >= firstDelBlock)
 		{
 			if (LocalRefCount[i] != 0)
 				elog(ERROR, "block %u of %s is still referenced (local %u)",
 					 bufHdr->tag.blockNum,
-					 relpathbackend(bufHdr->tag.rnode, MyBackendId,
+					 relpathbackend(bufHdr->tag.rnode.node, MyBackendId,
 									bufHdr->tag.forkNum),
 					 LocalRefCount[i]);
 			/* Remove entry from hashtable */
@@ -377,12 +377,12 @@ DropRelFileNodeAllLocalBuffers(RelFileNode rnode)
 		buf_state = pg_atomic_read_u32(&bufHdr->state);
 
 		if ((buf_state & BM_TAG_VALID) &&
-			RelFileNodeEquals(bufHdr->tag.rnode, rnode))
+			RelFileNodeEquals(bufHdr->tag.rnode.node, rnode))
 		{
 			if (LocalRefCount[i] != 0)
 				elog(ERROR, "block %u of %s is still referenced (local %u)",
 					 bufHdr->tag.blockNum,
-					 relpathbackend(bufHdr->tag.rnode, MyBackendId,
+					 relpathbackend(bufHdr->tag.rnode.node, MyBackendId,
 									bufHdr->tag.forkNum),
 					 LocalRefCount[i]);
 			/* Remove entry from hashtable */
diff --git a/src/backend/storage/freespace/fsmpage.c b/src/backend/storage/freespace/fsmpage.c
index cf7f03f..65eb422 100644
--- a/src/backend/storage/freespace/fsmpage.c
+++ b/src/backend/storage/freespace/fsmpage.c
@@ -268,13 +268,13 @@ restart:
 			 *
 			 * Fix the corruption and restart.
 			 */
-			RelFileNode rnode;
+			RelFileNodeBackend rnode;
 			ForkNumber	forknum;
 			BlockNumber blknum;
 
 			BufferGetTag(buf, &rnode, &forknum, &blknum);
 			elog(DEBUG1, "fixing corrupt FSM block %u, relation %u/%u/%u",
-				 blknum, rnode.spcNode, rnode.dbNode, rnode.relNode);
+				 blknum, rnode.node.spcNode, rnode.node.dbNode, rnode.node.relNode);
 
 			/* make sure we hold an exclusive lock */
 			if (!exclusive_lock_held)
diff --git a/src/backend/storage/smgr/md.c b/src/backend/storage/smgr/md.c
index 07f3c93..204c4cb 100644
--- a/src/backend/storage/smgr/md.c
+++ b/src/backend/storage/smgr/md.c
@@ -33,6 +33,7 @@
 #include "postmaster/bgwriter.h"
 #include "storage/fd.h"
 #include "storage/bufmgr.h"
+#include "storage/ipc.h"
 #include "storage/md.h"
 #include "storage/relfilenode.h"
 #include "storage/smgr.h"
@@ -87,6 +88,18 @@ typedef struct _MdfdVec
 
 static MemoryContext MdCxt;		/* context for all MdfdVec objects */
 
+/*
+ * Structure used to collect information created by this backend.
+ * Data of this related should be deleted on backend exit.
+ */
+typedef struct SessionRelation
+{
+	RelFileNodeBackend rnode;
+	struct SessionRelation* next;
+} SessionRelation;
+
+
+static SessionRelation* SessionRelations;
 
 /* Populate a file tag describing an md.c segment file. */
 #define INIT_MD_FILETAG(a,xx_rnode,xx_forknum,xx_segno) \
@@ -152,6 +165,48 @@ mdinit(void)
 								  ALLOCSET_DEFAULT_SIZES);
 }
 
+
+/*
+ * Delete all data of session relations and remove their pages from shared buffers.
+ * This function is called on backend exit.
+ */
+static void
+TruncateSessionRelations(int code, Datum arg)
+{
+	SessionRelation* rel;
+	for (rel = SessionRelations; rel != NULL; rel = rel->next)
+	{
+		/* Remove relation pages from shared buffers */
+		DropRelFileNodesAllBuffers(&rel->rnode, 1);
+
+		/* Delete relation files */
+		mdunlink(rel->rnode, InvalidForkNumber, false);
+	}
+}
+
+/*
+ * Maintain information about session relations accessed by this backend.
+ * This list is needed to perform cleanup on backend exit.
+ * Session relation is linked in this list when this relation is created or opened and file doesn't exist.
+ * Such procedure guarantee that each relation is linked into list only once.
+ */
+static void
+RegisterSessionRelation(SMgrRelation reln)
+{
+	SessionRelation* rel = (SessionRelation*)MemoryContextAlloc(TopMemoryContext, sizeof(SessionRelation));
+
+	/*
+	 * Perform session relation cleanup on backend exit. We are using shared memory hook, because
+	 * cleanup should be performed before backend is disconnected from shared memory.
+	 */
+	if (SessionRelations == NULL)
+		on_shmem_exit(TruncateSessionRelations, 0);
+
+	rel->rnode = reln->smgr_rnode;
+	rel->next = SessionRelations;
+	SessionRelations = rel;
+}
+
 /*
  *	mdexists() -- Does the physical file exist?
  *
@@ -218,6 +273,8 @@ mdcreate(SMgrRelation reln, ForkNumber forkNum, bool isRedo)
 					 errmsg("could not create file \"%s\": %m", path)));
 		}
 	}
+	if (RelFileNodeBackendIsGlobalTemp(reln->smgr_rnode))
+		RegisterSessionRelation(reln);
 
 	pfree(path);
 
@@ -465,6 +522,19 @@ mdopenfork(SMgrRelation reln, ForkNumber forknum, int behavior)
 
 	if (fd < 0)
 	{
+		/*
+		 * In case of session relation access, there may be no yet files of this relation for this backend.
+		 * If so, then create file and register session relation for truncation on backend exit.
+		 */
+		if (RelFileNodeBackendIsGlobalTemp(reln->smgr_rnode))
+		{
+			fd = PathNameOpenFile(path, O_RDWR | PG_BINARY | O_CREAT);
+			if (fd >= 0)
+			{
+				RegisterSessionRelation(reln);
+				goto NewSegment;
+			}
+		}
 		if ((behavior & EXTENSION_RETURN_NULL) &&
 			FILE_POSSIBLY_DELETED(errno))
 		{
@@ -476,6 +546,7 @@ mdopenfork(SMgrRelation reln, ForkNumber forknum, int behavior)
 				 errmsg("could not open file \"%s\": %m", path)));
 	}
 
+  NewSegment:
 	pfree(path);
 
 	_fdvec_resize(reln, forknum, 1);
@@ -652,8 +723,13 @@ mdread(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
 		 * complaining.  This allows, for example, the case of trying to
 		 * update a block that was later truncated away.
 		 */
-		if (zero_damaged_pages || InRecovery)
+		if (zero_damaged_pages || InRecovery || RelFileNodeBackendIsGlobalTemp(reln->smgr_rnode))
+		{
 			MemSet(buffer, 0, BLCKSZ);
+			/* In case of session relation we need to write zero page to provide correct result of subsequent mdnblocks */
+			if (RelFileNodeBackendIsGlobalTemp(reln->smgr_rnode))
+				mdwrite(reln, forknum, blocknum, buffer, true);
+		}
 		else
 			ereport(ERROR,
 					(errcode(ERRCODE_DATA_CORRUPTED),
@@ -738,12 +814,18 @@ mdwrite(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
 BlockNumber
 mdnblocks(SMgrRelation reln, ForkNumber forknum)
 {
-	MdfdVec    *v = mdopenfork(reln, forknum, EXTENSION_FAIL);
+	/*
+	 * If we access session relation, there may be no files yet of this relation for this backend.
+	 * Pass EXTENSION_RETURN_NULL to make mdopen return NULL in this case instead of reporting error.
+	 */
+	MdfdVec    *v = mdopenfork(reln, forknum, RelFileNodeBackendIsGlobalTemp(reln->smgr_rnode)
+							   ? EXTENSION_RETURN_NULL : EXTENSION_FAIL);
 	BlockNumber nblocks;
 	BlockNumber segno = 0;
 
 	/* mdopen has opened the first segment */
-	Assert(reln->md_num_open_segs[forknum] > 0);
+	if (reln->md_num_open_segs[forknum] == 0)
+		return 0;
 
 	/*
 	 * Start from the last open segments, to avoid redundant seeks.  We have
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index a87e721..2401361 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -994,6 +994,9 @@ pg_relation_filepath(PG_FUNCTION_ARGS)
 	/* Determine owning backend. */
 	switch (relform->relpersistence)
 	{
+		case RELPERSISTENCE_SESSION:
+			backend = BackendIdForSessionRelations();
+			break;
 		case RELPERSISTENCE_UNLOGGED:
 		case RELPERSISTENCE_PERMANENT:
 			backend = InvalidBackendId;
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index 2488607..86e8fca 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -1098,6 +1098,10 @@ RelationBuildDesc(Oid targetRelId, bool insertIt)
 	relation->rd_newRelfilenodeSubid = InvalidSubTransactionId;
 	switch (relation->rd_rel->relpersistence)
 	{
+		case RELPERSISTENCE_SESSION:
+			relation->rd_backend = BackendIdForSessionRelations();
+			relation->rd_islocaltemp = false;
+			break;
 		case RELPERSISTENCE_UNLOGGED:
 		case RELPERSISTENCE_PERMANENT:
 			relation->rd_backend = InvalidBackendId;
@@ -3301,6 +3305,10 @@ RelationBuildLocalRelation(const char *relname,
 	rel->rd_rel->relpersistence = relpersistence;
 	switch (relpersistence)
 	{
+		case RELPERSISTENCE_SESSION:
+			rel->rd_backend = BackendIdForSessionRelations();
+			rel->rd_islocaltemp = false;
+			break;
 		case RELPERSISTENCE_UNLOGGED:
 		case RELPERSISTENCE_PERMANENT:
 			rel->rd_backend = InvalidBackendId;
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 0cc9ede..1dff0c8 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -15593,8 +15593,8 @@ dumpTableSchema(Archive *fout, TableInfo *tbinfo)
 											 tbinfo->dobj.catId.oid, false);
 
 		appendPQExpBuffer(q, "CREATE %s%s %s",
-						  tbinfo->relpersistence == RELPERSISTENCE_UNLOGGED ?
-						  "UNLOGGED " : "",
+						  tbinfo->relpersistence == RELPERSISTENCE_UNLOGGED ? "UNLOGGED "
+						  : tbinfo->relpersistence == RELPERSISTENCE_SESSION ? "SESSION " : "",
 						  reltypename,
 						  qualrelname);
 
diff --git a/src/common/relpath.c b/src/common/relpath.c
index 62b9553..cef99d2 100644
--- a/src/common/relpath.c
+++ b/src/common/relpath.c
@@ -166,7 +166,18 @@ GetRelationPath(Oid dbNode, Oid spcNode, Oid relNode,
 		}
 		else
 		{
-			if (forkNumber != MAIN_FORKNUM)
+			/*
+			 * Session relations are distinguished from local temp relations by adding
+			 * SessionRelFirstBackendId offset to backendId.
+			 * These is no need to separate them at file system level, so just subtract SessionRelFirstBackendId
+			 * to avoid too long file names.
+			 * Segments of session relations have the same prefix (t%d_) as local temporary relations
+			 * to make it possible to cleanup them in the same way as local temporary relation files.
+			 */
+			 if (backendId >= SessionRelFirstBackendId)
+				 backendId -= SessionRelFirstBackendId;
+
+			 if (forkNumber != MAIN_FORKNUM)
 				path = psprintf("base/%u/t%d_%u_%s",
 								dbNode, backendId, relNode,
 								forkNames[forkNumber]);
diff --git a/src/include/catalog/pg_class.h b/src/include/catalog/pg_class.h
index 090b6ba..6a39663 100644
--- a/src/include/catalog/pg_class.h
+++ b/src/include/catalog/pg_class.h
@@ -165,6 +165,7 @@ typedef FormData_pg_class *Form_pg_class;
 #define		  RELPERSISTENCE_PERMANENT	'p' /* regular table */
 #define		  RELPERSISTENCE_UNLOGGED	'u' /* unlogged permanent table */
 #define		  RELPERSISTENCE_TEMP		't' /* temporary table */
+#define		  RELPERSISTENCE_SESSION	's' /* session table */
 
 /* default selection for replica identity (primary key or nothing) */
 #define		  REPLICA_IDENTITY_DEFAULT	'd'
diff --git a/src/include/storage/backendid.h b/src/include/storage/backendid.h
index 70ef8eb..f226e7c 100644
--- a/src/include/storage/backendid.h
+++ b/src/include/storage/backendid.h
@@ -22,6 +22,13 @@ typedef int BackendId;			/* unique currently active backend identifier */
 
 #define InvalidBackendId		(-1)
 
+/*
+ * We need to distinguish local and global temporary relations by RelFileNodeBackend.
+ * The least invasive change is to add some special bias value to backend id (since 
+ * maximal number of backed is limited by MaxBackends).
+ */
+#define SessionRelFirstBackendId (0x40000000)
+
 extern PGDLLIMPORT BackendId MyBackendId;	/* backend id of this backend */
 
 /* backend id of our parallel session leader, or InvalidBackendId if none */
@@ -34,4 +41,10 @@ extern PGDLLIMPORT BackendId ParallelMasterBackendId;
 #define BackendIdForTempRelations() \
 	(ParallelMasterBackendId == InvalidBackendId ? MyBackendId : ParallelMasterBackendId)
 
+
+#define BackendIdForSessionRelations() \
+	(BackendIdForTempRelations() + SessionRelFirstBackendId)
+
+#define IsSessionRelationBackendId(id) ((id) >= SessionRelFirstBackendId)
+
 #endif							/* BACKENDID_H */
diff --git a/src/include/storage/buf_internals.h b/src/include/storage/buf_internals.h
index df2dda7..7adb96b 100644
--- a/src/include/storage/buf_internals.h
+++ b/src/include/storage/buf_internals.h
@@ -90,16 +90,17 @@
  */
 typedef struct buftag
 {
-	RelFileNode rnode;			/* physical relation identifier */
+	RelFileNodeBackend rnode;			/* physical relation identifier */
 	ForkNumber	forkNum;
 	BlockNumber blockNum;		/* blknum relative to begin of reln */
 } BufferTag;
 
 #define CLEAR_BUFFERTAG(a) \
 ( \
-	(a).rnode.spcNode = InvalidOid, \
-	(a).rnode.dbNode = InvalidOid, \
-	(a).rnode.relNode = InvalidOid, \
+	(a).rnode.node.spcNode = InvalidOid, \
+	(a).rnode.node.dbNode = InvalidOid, \
+	(a).rnode.node.relNode = InvalidOid, \
+	(a).rnode.backend = InvalidBackendId, \
 	(a).forkNum = InvalidForkNumber, \
 	(a).blockNum = InvalidBlockNumber \
 )
@@ -113,7 +114,7 @@ typedef struct buftag
 
 #define BUFFERTAGS_EQUAL(a,b) \
 ( \
-	RelFileNodeEquals((a).rnode, (b).rnode) && \
+	RelFileNodeBackendEquals((a).rnode, (b).rnode) && \
 	(a).blockNum == (b).blockNum && \
 	(a).forkNum == (b).forkNum \
 )
diff --git a/src/include/storage/bufmgr.h b/src/include/storage/bufmgr.h
index 509f4b7..3315fa0 100644
--- a/src/include/storage/bufmgr.h
+++ b/src/include/storage/bufmgr.h
@@ -205,7 +205,7 @@ extern XLogRecPtr BufferGetLSNAtomic(Buffer buffer);
 extern void PrintPinnedBufs(void);
 #endif
 extern Size BufferShmemSize(void);
-extern void BufferGetTag(Buffer buffer, RelFileNode *rnode,
+extern void BufferGetTag(Buffer buffer, RelFileNodeBackend *rnode,
 						 ForkNumber *forknum, BlockNumber *blknum);
 
 extern void MarkBufferDirtyHint(Buffer buffer, bool buffer_std);
diff --git a/src/include/storage/bufpage.h b/src/include/storage/bufpage.h
index 4ef6d8d..bac7a31 100644
--- a/src/include/storage/bufpage.h
+++ b/src/include/storage/bufpage.h
@@ -229,6 +229,13 @@ typedef PageHeaderData *PageHeader;
 #define PageIsNew(page) (((PageHeader) (page))->pd_upper == 0)
 
 /*
+ * Page of temporary relation is not initialized
+ */
+#define GlobalTempRelationPageIsNotInitialized(rel, page) \
+	((rel)->rd_rel->relpersistence == RELPERSISTENCE_SESSION && PageIsNew(page))
+
+
+/*
  * PageGetItemId
  *		Returns an item identifier of a page.
  */
diff --git a/src/include/storage/relfilenode.h b/src/include/storage/relfilenode.h
index 586500a..20aec72 100644
--- a/src/include/storage/relfilenode.h
+++ b/src/include/storage/relfilenode.h
@@ -75,10 +75,25 @@ typedef struct RelFileNodeBackend
 	BackendId	backend;
 } RelFileNodeBackend;
 
+/*
+ * Check whether it is local or global temporary relation, which data belongs only to one backend.
+ */
 #define RelFileNodeBackendIsTemp(rnode) \
 	((rnode).backend != InvalidBackendId)
 
 /*
+ * Check whether it is global temporary relation which metadata is shared by all sessions,
+ * but data is private for the current session.
+ */
+#define RelFileNodeBackendIsGlobalTemp(rnode) IsSessionRelationBackendId((rnode).backend)
+
+/*
+ * Check whether it is local temporary relation which exists only in this backend.
+ */
+#define RelFileNodeBackendIsLocalTemp(rnode) \
+	(RelFileNodeBackendIsTemp(rnode) && !RelFileNodeBackendIsGlobalTemp(rnode))
+
+/*
  * Note: RelFileNodeEquals and RelFileNodeBackendEquals compare relNode first
  * since that is most likely to be different in two unequal RelFileNodes.  It
  * is probably redundant to compare spcNode if the other fields are found equal,
diff --git a/src/include/utils/rel.h b/src/include/utils/rel.h
index b0fe19e..b361851 100644
--- a/src/include/utils/rel.h
+++ b/src/include/utils/rel.h
@@ -328,6 +328,17 @@ typedef struct StdRdOptions
 	((relation)->rd_options ? \
 	 ((StdRdOptions *) (relation)->rd_options)->parallel_workers : (defaultpw))
 
+/*
+ * Relation persistence is either TEMP either SESSION
+ */
+#define IsLocalRelpersistence(relpersistence) \
+	((relpersistence) == RELPERSISTENCE_TEMP || (relpersistence) == RELPERSISTENCE_SESSION)
+
+/*
+ * Relation is either global either local temp table
+ */
+#define RelationHasSessionScope(relation) \
+	IsLocalRelpersistence(((relation)->rd_rel->relpersistence))
 
 /*
  * ViewOptions
diff --git a/src/test/isolation/expected/inherit-global-temp.out b/src/test/isolation/expected/inherit-global-temp.out
new file mode 100644
index 0000000..6114f8c
--- /dev/null
+++ b/src/test/isolation/expected/inherit-global-temp.out
@@ -0,0 +1,218 @@
+Parsed test spec with 2 sessions
+
+starting permutation: s1_insert_p s1_insert_c s2_insert_c s1_select_p s1_select_c s2_select_p s2_select_c
+step s1_insert_p: INSERT INTO inh_global_parent VALUES (1), (2);
+step s1_insert_c: INSERT INTO inh_global_temp_child_s1 VALUES (3), (4);
+step s2_insert_c: INSERT INTO inh_global_temp_child_s2 VALUES (5), (6);
+step s1_select_p: SELECT a FROM inh_global_parent;
+a              
+
+1              
+2              
+3              
+4              
+step s1_select_c: SELECT a FROM inh_global_temp_child_s1;
+a              
+
+3              
+4              
+step s2_select_p: SELECT a FROM inh_global_parent;
+a              
+
+1              
+2              
+5              
+6              
+step s2_select_c: SELECT a FROM inh_global_temp_child_s2;
+a              
+
+5              
+6              
+
+starting permutation: s1_insert_p s1_insert_c s2_insert_c s1_update_p s1_update_c s1_select_p s1_select_c s2_select_p s2_select_c
+step s1_insert_p: INSERT INTO inh_global_parent VALUES (1), (2);
+step s1_insert_c: INSERT INTO inh_global_temp_child_s1 VALUES (3), (4);
+step s2_insert_c: INSERT INTO inh_global_temp_child_s2 VALUES (5), (6);
+step s1_update_p: UPDATE inh_global_parent SET a = 11 WHERE a = 1;
+step s1_update_c: UPDATE inh_global_parent SET a = 13 WHERE a IN (3, 5);
+step s1_select_p: SELECT a FROM inh_global_parent;
+a              
+
+2              
+11             
+4              
+13             
+step s1_select_c: SELECT a FROM inh_global_temp_child_s1;
+a              
+
+4              
+13             
+step s2_select_p: SELECT a FROM inh_global_parent;
+a              
+
+2              
+11             
+5              
+6              
+step s2_select_c: SELECT a FROM inh_global_temp_child_s2;
+a              
+
+5              
+6              
+
+starting permutation: s1_insert_p s1_insert_c s2_insert_c s2_update_c s1_select_p s1_select_c s2_select_p s2_select_c
+step s1_insert_p: INSERT INTO inh_global_parent VALUES (1), (2);
+step s1_insert_c: INSERT INTO inh_global_temp_child_s1 VALUES (3), (4);
+step s2_insert_c: INSERT INTO inh_global_temp_child_s2 VALUES (5), (6);
+step s2_update_c: UPDATE inh_global_parent SET a = 15 WHERE a IN (3, 5);
+step s1_select_p: SELECT a FROM inh_global_parent;
+a              
+
+1              
+2              
+3              
+4              
+step s1_select_c: SELECT a FROM inh_global_temp_child_s1;
+a              
+
+3              
+4              
+step s2_select_p: SELECT a FROM inh_global_parent;
+a              
+
+1              
+2              
+6              
+15             
+step s2_select_c: SELECT a FROM inh_global_temp_child_s2;
+a              
+
+6              
+15             
+
+starting permutation: s1_insert_p s1_insert_c s2_insert_c s1_delete_p s1_delete_c s1_select_p s1_select_c s2_select_p s2_select_c
+step s1_insert_p: INSERT INTO inh_global_parent VALUES (1), (2);
+step s1_insert_c: INSERT INTO inh_global_temp_child_s1 VALUES (3), (4);
+step s2_insert_c: INSERT INTO inh_global_temp_child_s2 VALUES (5), (6);
+step s1_delete_p: DELETE FROM inh_global_parent WHERE a = 2;
+step s1_delete_c: DELETE FROM inh_global_parent WHERE a IN (4, 6);
+step s1_select_p: SELECT a FROM inh_global_parent;
+a              
+
+1              
+3              
+step s1_select_c: SELECT a FROM inh_global_temp_child_s1;
+a              
+
+3              
+step s2_select_p: SELECT a FROM inh_global_parent;
+a              
+
+1              
+5              
+6              
+step s2_select_c: SELECT a FROM inh_global_temp_child_s2;
+a              
+
+5              
+6              
+
+starting permutation: s1_insert_p s1_insert_c s2_insert_c s2_delete_c s1_select_p s1_select_c s2_select_p s2_select_c
+step s1_insert_p: INSERT INTO inh_global_parent VALUES (1), (2);
+step s1_insert_c: INSERT INTO inh_global_temp_child_s1 VALUES (3), (4);
+step s2_insert_c: INSERT INTO inh_global_temp_child_s2 VALUES (5), (6);
+step s2_delete_c: DELETE FROM inh_global_parent WHERE a IN (4, 6);
+step s1_select_p: SELECT a FROM inh_global_parent;
+a              
+
+1              
+2              
+3              
+4              
+step s1_select_c: SELECT a FROM inh_global_temp_child_s1;
+a              
+
+3              
+4              
+step s2_select_p: SELECT a FROM inh_global_parent;
+a              
+
+1              
+2              
+5              
+step s2_select_c: SELECT a FROM inh_global_temp_child_s2;
+a              
+
+5              
+
+starting permutation: s1_insert_p s1_insert_c s2_insert_c s1_truncate_p s1_select_p s1_select_c s2_select_p s2_select_c
+step s1_insert_p: INSERT INTO inh_global_parent VALUES (1), (2);
+step s1_insert_c: INSERT INTO inh_global_temp_child_s1 VALUES (3), (4);
+step s2_insert_c: INSERT INTO inh_global_temp_child_s2 VALUES (5), (6);
+step s1_truncate_p: TRUNCATE inh_global_parent;
+step s1_select_p: SELECT a FROM inh_global_parent;
+a              
+
+step s1_select_c: SELECT a FROM inh_global_temp_child_s1;
+a              
+
+step s2_select_p: SELECT a FROM inh_global_parent;
+a              
+
+5              
+6              
+step s2_select_c: SELECT a FROM inh_global_temp_child_s2;
+a              
+
+5              
+6              
+
+starting permutation: s1_insert_p s1_insert_c s2_insert_c s2_truncate_p s1_select_p s1_select_c s2_select_p s2_select_c
+step s1_insert_p: INSERT INTO inh_global_parent VALUES (1), (2);
+step s1_insert_c: INSERT INTO inh_global_temp_child_s1 VALUES (3), (4);
+step s2_insert_c: INSERT INTO inh_global_temp_child_s2 VALUES (5), (6);
+step s2_truncate_p: TRUNCATE inh_global_parent;
+step s1_select_p: SELECT a FROM inh_global_parent;
+a              
+
+3              
+4              
+step s1_select_c: SELECT a FROM inh_global_temp_child_s1;
+a              
+
+3              
+4              
+step s2_select_p: SELECT a FROM inh_global_parent;
+a              
+
+step s2_select_c: SELECT a FROM inh_global_temp_child_s2;
+a              
+
+
+starting permutation: s1_insert_p s1_insert_c s2_insert_c s1_begin s1_truncate_p s2_select_p s1_commit
+step s1_insert_p: INSERT INTO inh_global_parent VALUES (1), (2);
+step s1_insert_c: INSERT INTO inh_global_temp_child_s1 VALUES (3), (4);
+step s2_insert_c: INSERT INTO inh_global_temp_child_s2 VALUES (5), (6);
+step s1_begin: BEGIN;
+step s1_truncate_p: TRUNCATE inh_global_parent;
+step s2_select_p: SELECT a FROM inh_global_parent; <waiting ...>
+step s1_commit: COMMIT;
+step s2_select_p: <... completed>
+a              
+
+5              
+6              
+
+starting permutation: s1_insert_p s1_insert_c s2_insert_c s1_begin s1_truncate_p s2_select_c s1_commit
+step s1_insert_p: INSERT INTO inh_global_parent VALUES (1), (2);
+step s1_insert_c: INSERT INTO inh_global_temp_child_s1 VALUES (3), (4);
+step s2_insert_c: INSERT INTO inh_global_temp_child_s2 VALUES (5), (6);
+step s1_begin: BEGIN;
+step s1_truncate_p: TRUNCATE inh_global_parent;
+step s2_select_c: SELECT a FROM inh_global_temp_child_s2; <waiting ...>
+step s1_commit: COMMIT;
+step s2_select_c: <... completed>
+a              
+
+5              
+6              
diff --git a/src/test/isolation/isolation_schedule b/src/test/isolation/isolation_schedule
index 74b5077..44df4e0 100644
--- a/src/test/isolation/isolation_schedule
+++ b/src/test/isolation/isolation_schedule
@@ -85,3 +85,4 @@ test: plpgsql-toast
 test: truncate-conflict
 test: serializable-parallel
 test: serializable-parallel-2
+test: inherit-global-temp
diff --git a/src/test/isolation/specs/inherit-global-temp.spec b/src/test/isolation/specs/inherit-global-temp.spec
new file mode 100644
index 0000000..5e95dd6
--- /dev/null
+++ b/src/test/isolation/specs/inherit-global-temp.spec
@@ -0,0 +1,73 @@
+# This is a copy of the inherit-temp test with little changes for global temporary tables.
+#
+
+setup
+{
+  CREATE TABLE inh_global_parent (a int);
+}
+
+teardown
+{
+  DROP TABLE inh_global_parent;
+}
+
+# Session 1 executes actions which act directly on both the parent and
+# its child.  Abbreviation "c" is used for queries working on the child
+# and "p" on the parent.
+session "s1"
+setup
+{
+  CREATE GLOBAL TEMPORARY TABLE inh_global_temp_child_s1 () INHERITS (inh_global_parent);
+}
+step "s1_begin" { BEGIN; }
+step "s1_truncate_p" { TRUNCATE inh_global_parent; }
+step "s1_select_p" { SELECT a FROM inh_global_parent; }
+step "s1_select_c" { SELECT a FROM inh_global_temp_child_s1; }
+step "s1_insert_p" { INSERT INTO inh_global_parent VALUES (1), (2); }
+step "s1_insert_c" { INSERT INTO inh_global_temp_child_s1 VALUES (3), (4); }
+step "s1_update_p" { UPDATE inh_global_parent SET a = 11 WHERE a = 1; }
+step "s1_update_c" { UPDATE inh_global_parent SET a = 13 WHERE a IN (3, 5); }
+step "s1_delete_p" { DELETE FROM inh_global_parent WHERE a = 2; }
+step "s1_delete_c" { DELETE FROM inh_global_parent WHERE a IN (4, 6); }
+step "s1_commit" { COMMIT; }
+teardown
+{
+  DROP TABLE inh_global_temp_child_s1;
+}
+
+# Session 2 executes actions on the parent which act only on the child.
+session "s2"
+setup
+{
+  CREATE GLOBAL TEMPORARY TABLE inh_global_temp_child_s2 () INHERITS (inh_global_parent);
+}
+step "s2_truncate_p" { TRUNCATE inh_global_parent; }
+step "s2_select_p" { SELECT a FROM inh_global_parent; }
+step "s2_select_c" { SELECT a FROM inh_global_temp_child_s2; }
+step "s2_insert_c" { INSERT INTO inh_global_temp_child_s2 VALUES (5), (6); }
+step "s2_update_c" { UPDATE inh_global_parent SET a = 15 WHERE a IN (3, 5); }
+step "s2_delete_c" { DELETE FROM inh_global_parent WHERE a IN (4, 6); }
+teardown
+{
+  DROP TABLE inh_global_temp_child_s2;
+}
+
+# Check INSERT behavior across sessions
+permutation "s1_insert_p" "s1_insert_c" "s2_insert_c" "s1_select_p" "s1_select_c" "s2_select_p" "s2_select_c"
+
+# Check UPDATE behavior across sessions
+permutation "s1_insert_p" "s1_insert_c" "s2_insert_c" "s1_update_p" "s1_update_c" "s1_select_p" "s1_select_c" "s2_select_p" "s2_select_c"
+permutation "s1_insert_p" "s1_insert_c" "s2_insert_c" "s2_update_c" "s1_select_p" "s1_select_c" "s2_select_p" "s2_select_c"
+
+# Check DELETE behavior across sessions
+permutation "s1_insert_p" "s1_insert_c" "s2_insert_c" "s1_delete_p" "s1_delete_c" "s1_select_p" "s1_select_c" "s2_select_p" "s2_select_c"
+permutation "s1_insert_p" "s1_insert_c" "s2_insert_c" "s2_delete_c" "s1_select_p" "s1_select_c" "s2_select_p" "s2_select_c"
+
+# Check TRUNCATE behavior across sessions
+permutation "s1_insert_p" "s1_insert_c" "s2_insert_c" "s1_truncate_p" "s1_select_p" "s1_select_c" "s2_select_p" "s2_select_c"
+permutation "s1_insert_p" "s1_insert_c" "s2_insert_c" "s2_truncate_p" "s1_select_p" "s1_select_c" "s2_select_p" "s2_select_c"
+
+# TRUNCATE on a parent tree does not block access to temporary child relation
+# of another session, and blocks when scanning the parent.
+permutation "s1_insert_p" "s1_insert_c" "s2_insert_c" "s1_begin" "s1_truncate_p" "s2_select_p" "s1_commit"
+permutation "s1_insert_p" "s1_insert_c" "s2_insert_c" "s1_begin" "s1_truncate_p" "s2_select_c" "s1_commit"
diff --git a/src/test/regress/expected/global_temp.out b/src/test/regress/expected/global_temp.out
new file mode 100644
index 0000000..ae1adb6
--- /dev/null
+++ b/src/test/regress/expected/global_temp.out
@@ -0,0 +1,247 @@
+--
+-- GLOBAL TEMP
+-- Test global temp relations
+--
+-- Test ON COMMIT DELETE ROWS
+CREATE GLOBAL TEMP TABLE global_temptest(col int) ON COMMIT DELETE ROWS;
+BEGIN;
+INSERT INTO global_temptest VALUES (1);
+INSERT INTO global_temptest VALUES (2);
+SELECT * FROM global_temptest;
+ col 
+-----
+   1
+   2
+(2 rows)
+
+COMMIT;
+SELECT * FROM global_temptest;
+ col 
+-----
+(0 rows)
+
+DROP TABLE global_temptest;
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temptest(col) ON COMMIT DELETE ROWS AS SELECT 1;
+SELECT * FROM global_temptest;
+ col 
+-----
+   1
+(1 row)
+
+COMMIT;
+SELECT * FROM global_temptest;
+ col 
+-----
+(0 rows)
+
+DROP TABLE global_temptest;
+-- Test foreign keys
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temptest1(col int PRIMARY KEY);
+CREATE GLOBAL TEMP TABLE global_temptest2(col int REFERENCES global_temptest1)
+  ON COMMIT DELETE ROWS;
+INSERT INTO global_temptest1 VALUES (1);
+INSERT INTO global_temptest2 VALUES (1);
+COMMIT;
+SELECT * FROM global_temptest1;
+ col 
+-----
+   1
+(1 row)
+
+SELECT * FROM global_temptest2;
+ col 
+-----
+(0 rows)
+
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temptest3(col int PRIMARY KEY) ON COMMIT DELETE ROWS;
+CREATE GLOBAL TEMP TABLE global_temptest4(col int REFERENCES global_temptest3);
+COMMIT;
+ERROR:  unsupported ON COMMIT and foreign key combination
+DETAIL:  Table "global_temptest4" references "global_temptest3", but they do not have the same ON COMMIT setting.
+-- For partitioned temp tables, ON COMMIT actions ignore storage-less
+-- partitioned tables.
+BEGIN;
+CREATE GLOBAL TEMP TABLE temp_parted_oncommit (a int)
+  PARTITION BY LIST (a) ON COMMIT DELETE ROWS;
+CREATE GLOBAL TEMP TABLE temp_parted_oncommit_1
+  PARTITION OF temp_parted_oncommit
+  FOR VALUES IN (1) ON COMMIT DELETE ROWS;
+INSERT INTO temp_parted_oncommit VALUES (1);
+COMMIT;
+-- partitions are emptied by the previous commit
+SELECT * FROM temp_parted_oncommit;
+ a 
+---
+(0 rows)
+
+DROP TABLE temp_parted_oncommit;
+-- Using ON COMMIT DELETE on a partitioned table does not remove
+-- all rows if partitions preserve their data.
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temp_parted_oncommit_test (a int)
+  PARTITION BY LIST (a) ON COMMIT DELETE ROWS;
+CREATE GLOBAL TEMP TABLE global_temp_parted_oncommit_test1
+  PARTITION OF global_temp_parted_oncommit_test
+  FOR VALUES IN (1) ON COMMIT PRESERVE ROWS;
+INSERT INTO global_temp_parted_oncommit_test VALUES (1);
+COMMIT;
+-- Data from the remaining partition is still here as its rows are
+-- preserved.
+SELECT * FROM global_temp_parted_oncommit_test;
+ a 
+---
+ 1
+(1 row)
+
+-- two relations remain in this case.
+SELECT relname FROM pg_class WHERE relname LIKE 'global_temp_parted_oncommit_test%';
+              relname              
+-----------------------------------
+ global_temp_parted_oncommit_test
+ global_temp_parted_oncommit_test1
+(2 rows)
+
+DROP TABLE global_temp_parted_oncommit_test;
+-- Check dependencies between ON COMMIT actions with inheritance trees.
+-- Data on the parent is removed, and the child goes away.
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temp_inh_oncommit_test (a int) ON COMMIT DELETE ROWS;
+CREATE GLOBAL TEMP TABLE global_temp_inh_oncommit_test1 ()
+  INHERITS(global_temp_inh_oncommit_test) ON COMMIT PRESERVE ROWS;
+INSERT INTO global_temp_inh_oncommit_test1 VALUES (1);
+INSERT INTO global_temp_inh_oncommit_test VALUES (1);
+COMMIT;
+SELECT * FROM global_temp_inh_oncommit_test;
+ a 
+---
+ 1
+(1 row)
+
+-- two relations remain
+SELECT relname FROM pg_class WHERE relname LIKE 'global_temp_inh_oncommit_test%';
+            relname             
+--------------------------------
+ global_temp_inh_oncommit_test
+ global_temp_inh_oncommit_test1
+(2 rows)
+
+DROP TABLE global_temp_inh_oncommit_test1;
+DROP TABLE global_temp_inh_oncommit_test;
+-- Global temp table cannot inherit from temporary relation
+BEGIN;
+CREATE TEMP TABLE global_temp_table (a int) ON COMMIT DELETE ROWS;
+CREATE GLOBAL TEMP TABLE global_temp_table1 ()
+  INHERITS(global_temp_table) ON COMMIT PRESERVE ROWS;
+ERROR:  cannot inherit from temporary relation "global_temp_table"
+ROLLBACK;
+-- Temp table can inherit from global temporary relation
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temp_table (a int) ON COMMIT DELETE ROWS;
+CREATE TEMP TABLE temp_table1 ()
+  INHERITS(global_temp_table) ON COMMIT PRESERVE ROWS;
+CREATE TEMP TABLE temp_table2 ()
+  INHERITS(global_temp_table) ON COMMIT DELETE ROWS;
+INSERT INTO temp_table2 VALUES (2);
+INSERT INTO temp_table1 VALUES (1);
+INSERT INTO global_temp_table VALUES (0);
+SELECT * FROM global_temp_table;
+ a 
+---
+ 0
+ 1
+ 2
+(3 rows)
+
+COMMIT;
+SELECT * FROM global_temp_table;
+ a 
+---
+ 1
+(1 row)
+
+DROP TABLE temp_table2;
+DROP TABLE temp_table1;
+DROP TABLE global_temp_table;
+-- Global temp table can inherit from normal relation
+BEGIN;
+CREATE TABLE normal_table (a int);
+CREATE GLOBAL TEMP TABLE temp_table1 ()
+  INHERITS(normal_table) ON COMMIT PRESERVE ROWS;
+CREATE GLOBAL TEMP TABLE temp_table2 ()
+  INHERITS(normal_table) ON COMMIT DELETE ROWS;
+INSERT INTO temp_table2 VALUES (2);
+INSERT INTO temp_table1 VALUES (1);
+INSERT INTO normal_table VALUES (0);
+SELECT * FROM normal_table;
+ a 
+---
+ 0
+ 1
+ 2
+(3 rows)
+
+COMMIT;
+SELECT * FROM normal_table;
+ a 
+---
+ 0
+ 1
+(2 rows)
+
+DROP TABLE temp_table2;
+DROP TABLE temp_table1;
+DROP TABLE normal_table;
+-- Check SERIAL and BIGSERIAL pseudo-types
+CREATE GLOBAL TEMP TABLE global_temp_table ( aid BIGSERIAL, bid SERIAL );
+CREATE SEQUENCE test_sequence;
+INSERT INTO global_temp_table DEFAULT VALUES;
+INSERT INTO global_temp_table DEFAULT VALUES;
+INSERT INTO global_temp_table DEFAULT VALUES;
+SELECT * FROM global_temp_table;
+ aid | bid 
+-----+-----
+   1 |   1
+   2 |   2
+   3 |   3
+(3 rows)
+
+SELECT NEXTVAL( 'test_sequence' );
+ nextval 
+---------
+       1
+(1 row)
+
+\c
+SELECT * FROM global_temp_table;
+ aid | bid 
+-----+-----
+(0 rows)
+
+SELECT NEXTVAL( 'test_sequence' );
+ nextval 
+---------
+       2
+(1 row)
+
+INSERT INTO global_temp_table DEFAULT VALUES;
+INSERT INTO global_temp_table DEFAULT VALUES;
+INSERT INTO global_temp_table DEFAULT VALUES;
+SELECT * FROM global_temp_table;
+ aid | bid 
+-----+-----
+   1 |   1
+   2 |   2
+   3 |   3
+(3 rows)
+
+SELECT NEXTVAL( 'test_sequence' );
+ nextval 
+---------
+       3
+(1 row)
+
+DROP TABLE global_temp_table;
+DROP SEQUENCE test_sequence;
diff --git a/src/test/regress/expected/session_table.out b/src/test/regress/expected/session_table.out
new file mode 100644
index 0000000..1b9b3f4
--- /dev/null
+++ b/src/test/regress/expected/session_table.out
@@ -0,0 +1,64 @@
+create session table my_private_table(x integer primary key, y integer);
+insert into my_private_table values (generate_series(1,10000), generate_series(1,10000));
+select count(*) from my_private_table;
+ count 
+-------
+ 10000
+(1 row)
+
+\c
+select count(*) from my_private_table;
+ count 
+-------
+     0
+(1 row)
+
+select * from my_private_table where x=10001;
+ x | y 
+---+---
+(0 rows)
+
+insert into my_private_table values (generate_series(1,100000), generate_series(1,100000));
+create index on my_private_table(y);
+select * from my_private_table where x=10001;
+   x   |   y   
+-------+-------
+ 10001 | 10001
+(1 row)
+
+select * from my_private_table where y=10001;
+   x   |   y   
+-------+-------
+ 10001 | 10001
+(1 row)
+
+select count(*) from my_private_table;
+ count  
+--------
+ 100000
+(1 row)
+
+\c
+select * from my_private_table where x=100001;
+ x | y 
+---+---
+(0 rows)
+
+select * from my_private_table order by y desc limit 1;
+ x | y 
+---+---
+(0 rows)
+
+insert into my_private_table values (generate_series(1,100000), generate_series(1,100000));
+select * from my_private_table where x=100001;
+ x | y 
+---+---
+(0 rows)
+
+select * from my_private_table order by y desc limit 1;
+   x    |   y    
+--------+--------
+ 100000 | 100000
+(1 row)
+
+drop table  my_private_table;
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index fc0f141..507cf7d 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -107,7 +107,7 @@ test: json jsonb json_encoding jsonpath jsonpath_encoding jsonb_jsonpath
 # NB: temp.sql does a reconnect which transiently uses 2 connections,
 # so keep this parallel group to at most 19 tests
 # ----------
-test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion truncate alter_table sequence polymorphism rowtypes returning largeobject with xml
+test: plancache limit plpgsql copy2 temp global_temp session_table domain rangefuncs prepare conversion truncate alter_table sequence polymorphism rowtypes returning largeobject with xml
 
 # ----------
 # Another group of parallel tests
diff --git a/src/test/regress/serial_schedule b/src/test/regress/serial_schedule
index 68ac56a..3890777 100644
--- a/src/test/regress/serial_schedule
+++ b/src/test/regress/serial_schedule
@@ -172,6 +172,8 @@ test: limit
 test: plpgsql
 test: copy2
 test: temp
+test: global_temp
+test: session_table
 test: domain
 test: rangefuncs
 test: prepare
diff --git a/src/test/regress/sql/global_temp.sql b/src/test/regress/sql/global_temp.sql
new file mode 100644
index 0000000..3058b9b
--- /dev/null
+++ b/src/test/regress/sql/global_temp.sql
@@ -0,0 +1,151 @@
+--
+-- GLOBAL TEMP
+-- Test global temp relations
+--
+
+-- Test ON COMMIT DELETE ROWS
+
+CREATE GLOBAL TEMP TABLE global_temptest(col int) ON COMMIT DELETE ROWS;
+
+BEGIN;
+INSERT INTO global_temptest VALUES (1);
+INSERT INTO global_temptest VALUES (2);
+
+SELECT * FROM global_temptest;
+COMMIT;
+
+SELECT * FROM global_temptest;
+
+DROP TABLE global_temptest;
+
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temptest(col) ON COMMIT DELETE ROWS AS SELECT 1;
+
+SELECT * FROM global_temptest;
+COMMIT;
+
+SELECT * FROM global_temptest;
+
+DROP TABLE global_temptest;
+
+-- Test foreign keys
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temptest1(col int PRIMARY KEY);
+CREATE GLOBAL TEMP TABLE global_temptest2(col int REFERENCES global_temptest1)
+  ON COMMIT DELETE ROWS;
+INSERT INTO global_temptest1 VALUES (1);
+INSERT INTO global_temptest2 VALUES (1);
+COMMIT;
+SELECT * FROM global_temptest1;
+SELECT * FROM global_temptest2;
+
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temptest3(col int PRIMARY KEY) ON COMMIT DELETE ROWS;
+CREATE GLOBAL TEMP TABLE global_temptest4(col int REFERENCES global_temptest3);
+COMMIT;
+
+-- For partitioned temp tables, ON COMMIT actions ignore storage-less
+-- partitioned tables.
+BEGIN;
+CREATE GLOBAL TEMP TABLE temp_parted_oncommit (a int)
+  PARTITION BY LIST (a) ON COMMIT DELETE ROWS;
+CREATE GLOBAL TEMP TABLE temp_parted_oncommit_1
+  PARTITION OF temp_parted_oncommit
+  FOR VALUES IN (1) ON COMMIT DELETE ROWS;
+INSERT INTO temp_parted_oncommit VALUES (1);
+COMMIT;
+-- partitions are emptied by the previous commit
+SELECT * FROM temp_parted_oncommit;
+DROP TABLE temp_parted_oncommit;
+
+-- Using ON COMMIT DELETE on a partitioned table does not remove
+-- all rows if partitions preserve their data.
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temp_parted_oncommit_test (a int)
+  PARTITION BY LIST (a) ON COMMIT DELETE ROWS;
+CREATE GLOBAL TEMP TABLE global_temp_parted_oncommit_test1
+  PARTITION OF global_temp_parted_oncommit_test
+  FOR VALUES IN (1) ON COMMIT PRESERVE ROWS;
+INSERT INTO global_temp_parted_oncommit_test VALUES (1);
+COMMIT;
+-- Data from the remaining partition is still here as its rows are
+-- preserved.
+SELECT * FROM global_temp_parted_oncommit_test;
+-- two relations remain in this case.
+SELECT relname FROM pg_class WHERE relname LIKE 'global_temp_parted_oncommit_test%';
+DROP TABLE global_temp_parted_oncommit_test;
+
+-- Check dependencies between ON COMMIT actions with inheritance trees.
+-- Data on the parent is removed, and the child goes away.
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temp_inh_oncommit_test (a int) ON COMMIT DELETE ROWS;
+CREATE GLOBAL TEMP TABLE global_temp_inh_oncommit_test1 ()
+  INHERITS(global_temp_inh_oncommit_test) ON COMMIT PRESERVE ROWS;
+INSERT INTO global_temp_inh_oncommit_test1 VALUES (1);
+INSERT INTO global_temp_inh_oncommit_test VALUES (1);
+COMMIT;
+SELECT * FROM global_temp_inh_oncommit_test;
+-- two relations remain
+SELECT relname FROM pg_class WHERE relname LIKE 'global_temp_inh_oncommit_test%';
+DROP TABLE global_temp_inh_oncommit_test1;
+DROP TABLE global_temp_inh_oncommit_test;
+
+-- Global temp table cannot inherit from temporary relation
+BEGIN;
+CREATE TEMP TABLE global_temp_table (a int) ON COMMIT DELETE ROWS;
+CREATE GLOBAL TEMP TABLE global_temp_table1 ()
+  INHERITS(global_temp_table) ON COMMIT PRESERVE ROWS;
+ROLLBACK;
+
+-- Temp table can inherit from global temporary relation
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temp_table (a int) ON COMMIT DELETE ROWS;
+CREATE TEMP TABLE temp_table1 ()
+  INHERITS(global_temp_table) ON COMMIT PRESERVE ROWS;
+CREATE TEMP TABLE temp_table2 ()
+  INHERITS(global_temp_table) ON COMMIT DELETE ROWS;
+INSERT INTO temp_table2 VALUES (2);
+INSERT INTO temp_table1 VALUES (1);
+INSERT INTO global_temp_table VALUES (0);
+SELECT * FROM global_temp_table;
+COMMIT;
+SELECT * FROM global_temp_table;
+DROP TABLE temp_table2;
+DROP TABLE temp_table1;
+DROP TABLE global_temp_table;
+
+-- Global temp table can inherit from normal relation
+BEGIN;
+CREATE TABLE normal_table (a int);
+CREATE GLOBAL TEMP TABLE temp_table1 ()
+  INHERITS(normal_table) ON COMMIT PRESERVE ROWS;
+CREATE GLOBAL TEMP TABLE temp_table2 ()
+  INHERITS(normal_table) ON COMMIT DELETE ROWS;
+INSERT INTO temp_table2 VALUES (2);
+INSERT INTO temp_table1 VALUES (1);
+INSERT INTO normal_table VALUES (0);
+SELECT * FROM normal_table;
+COMMIT;
+SELECT * FROM normal_table;
+DROP TABLE temp_table2;
+DROP TABLE temp_table1;
+DROP TABLE normal_table;
+
+-- Check SERIAL and BIGSERIAL pseudo-types
+CREATE GLOBAL TEMP TABLE global_temp_table ( aid BIGSERIAL, bid SERIAL );
+CREATE SEQUENCE test_sequence;
+INSERT INTO global_temp_table DEFAULT VALUES;
+INSERT INTO global_temp_table DEFAULT VALUES;
+INSERT INTO global_temp_table DEFAULT VALUES;
+SELECT * FROM global_temp_table;
+SELECT NEXTVAL( 'test_sequence' );
+\c
+SELECT * FROM global_temp_table;
+SELECT NEXTVAL( 'test_sequence' );
+INSERT INTO global_temp_table DEFAULT VALUES;
+INSERT INTO global_temp_table DEFAULT VALUES;
+INSERT INTO global_temp_table DEFAULT VALUES;
+SELECT * FROM global_temp_table;
+SELECT NEXTVAL( 'test_sequence' );
+DROP TABLE global_temp_table;
+DROP SEQUENCE test_sequence;
diff --git a/src/test/regress/sql/session_table.sql b/src/test/regress/sql/session_table.sql
new file mode 100644
index 0000000..c6663dc
--- /dev/null
+++ b/src/test/regress/sql/session_table.sql
@@ -0,0 +1,18 @@
+create session table my_private_table(x integer primary key, y integer);
+insert into my_private_table values (generate_series(1,10000), generate_series(1,10000));
+select count(*) from my_private_table;
+\c
+select count(*) from my_private_table;
+select * from my_private_table where x=10001;
+insert into my_private_table values (generate_series(1,100000), generate_series(1,100000));
+create index on my_private_table(y);
+select * from my_private_table where x=10001;
+select * from my_private_table where y=10001;
+select count(*) from my_private_table;
+\c
+select * from my_private_table where x=100001;
+select * from my_private_table order by y desc limit 1;
+insert into my_private_table values (generate_series(1,100000), generate_series(1,100000));
+select * from my_private_table where x=100001;
+select * from my_private_table order by y desc limit 1;
+drop table  my_private_table;
diff --git a/src/backend/access/gist/gistutil.c b/src/backend/access/gist/gistutil.c
index 9726020..c99701d 100644
--- a/src/backend/access/gist/gistutil.c
+++ b/src/backend/access/gist/gistutil.c
@@ -1028,7 +1028,7 @@ gistGetFakeLSN(Relation rel)
 {
 	static XLogRecPtr counter = FirstNormalUnloggedLSN;
 
-	if (rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP)
+	if (RelationHasSessionScope(rel))
 	{
 		/*
 		 * Temporary relations are only accessible in our session, so a simple
diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index f1ff01e..e92d324 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -673,6 +673,7 @@ heapam_relation_copy_data(Relation rel, const RelFileNode *newrnode)
 			 * init fork of an unlogged relation.
 			 */
 			if (rel->rd_rel->relpersistence == RELPERSISTENCE_PERMANENT ||
+				rel->rd_rel->relpersistence == RELPERSISTENCE_SESSION ||
 				(rel->rd_rel->relpersistence == RELPERSISTENCE_UNLOGGED &&
 				 forkNum == INIT_FORKNUM))
 				log_smgrcreate(newrnode, forkNum);
diff --git a/src/backend/access/nbtree/nbtpage.c b/src/backend/access/nbtree/nbtpage.c
index 9c1f7de..97cc9e4 100644
--- a/src/backend/access/nbtree/nbtpage.c
+++ b/src/backend/access/nbtree/nbtpage.c
@@ -763,7 +763,11 @@ _bt_getbuf(Relation rel, BlockNumber blkno, int access)
 		/* Read an existing block of the relation */
 		buf = ReadBuffer(rel, blkno);
 		LockBuffer(buf, access);
-		_bt_checkpage(rel, buf);
+		/* Session temporary relation may be not yet initialized for this backend. */
+		if (blkno == BTREE_METAPAGE && GlobalTempRelationPageIsNotInitialized(rel, BufferGetPage(buf)))
+			_bt_initmetapage(BufferGetPage(buf), P_NONE, 0);
+		else
+			_bt_checkpage(rel, buf);
 	}
 	else
 	{
diff --git a/src/backend/catalog/catalog.c b/src/backend/catalog/catalog.c
index a065419..8814afb 100644
--- a/src/backend/catalog/catalog.c
+++ b/src/backend/catalog/catalog.c
@@ -409,6 +409,9 @@ GetNewRelFileNode(Oid reltablespace, Relation pg_class, char relpersistence)
 		case RELPERSISTENCE_TEMP:
 			backend = BackendIdForTempRelations();
 			break;
+		case RELPERSISTENCE_SESSION:
+			backend = BackendIdForSessionRelations();
+			break;
 		case RELPERSISTENCE_UNLOGGED:
 		case RELPERSISTENCE_PERMANENT:
 			backend = InvalidBackendId;
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 3e1d406..aaa2c49 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -3590,7 +3590,7 @@ reindex_relation(Oid relid, int flags, int options)
 		if (flags & REINDEX_REL_FORCE_INDEXES_UNLOGGED)
 			persistence = RELPERSISTENCE_UNLOGGED;
 		else if (flags & REINDEX_REL_FORCE_INDEXES_PERMANENT)
-			persistence = RELPERSISTENCE_PERMANENT;
+			persistence = rel->rd_rel->relpersistence == RELPERSISTENCE_SESSION ? RELPERSISTENCE_SESSION : RELPERSISTENCE_PERMANENT;
 		else
 			persistence = rel->rd_rel->relpersistence;
 
diff --git a/src/backend/catalog/storage.c b/src/backend/catalog/storage.c
index 3cc886f..a111ddc 100644
--- a/src/backend/catalog/storage.c
+++ b/src/backend/catalog/storage.c
@@ -93,6 +93,10 @@ RelationCreateStorage(RelFileNode rnode, char relpersistence)
 			backend = InvalidBackendId;
 			needs_wal = false;
 			break;
+		case RELPERSISTENCE_SESSION:
+			backend = BackendIdForSessionRelations();
+			needs_wal = false;
+			break;
 		case RELPERSISTENCE_PERMANENT:
 			backend = InvalidBackendId;
 			needs_wal = true;
diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c
index cedb4ee..d11c5b3 100644
--- a/src/backend/commands/cluster.c
+++ b/src/backend/commands/cluster.c
@@ -1400,7 +1400,7 @@ finish_heap_swap(Oid OIDOldHeap, Oid OIDNewHeap,
 	 */
 	if (newrelpersistence == RELPERSISTENCE_UNLOGGED)
 		reindex_flags |= REINDEX_REL_FORCE_INDEXES_UNLOGGED;
-	else if (newrelpersistence == RELPERSISTENCE_PERMANENT)
+	else if (newrelpersistence != RELPERSISTENCE_TEMP)
 		reindex_flags |= REINDEX_REL_FORCE_INDEXES_PERMANENT;
 
 	/* Report that we are now reindexing relations */
diff --git a/src/backend/commands/sequence.c b/src/backend/commands/sequence.c
index 0960b33..6c3998f 100644
--- a/src/backend/commands/sequence.c
+++ b/src/backend/commands/sequence.c
@@ -94,7 +94,7 @@ static HTAB *seqhashtab = NULL; /* hash table for SeqTable items */
  */
 static SeqTableData *last_used_seq = NULL;
 
-static void fill_seq_with_data(Relation rel, HeapTuple tuple);
+static void fill_seq_with_data(Relation rel, HeapTuple tuple, Buffer buf);
 static Relation lock_and_open_sequence(SeqTable seq);
 static void create_seq_hashtable(void);
 static void init_sequence(Oid relid, SeqTable *p_elm, Relation *p_rel);
@@ -222,7 +222,7 @@ DefineSequence(ParseState *pstate, CreateSeqStmt *seq)
 
 	/* now initialize the sequence's data */
 	tuple = heap_form_tuple(tupDesc, value, null);
-	fill_seq_with_data(rel, tuple);
+	fill_seq_with_data(rel, tuple, InvalidBuffer);
 
 	/* process OWNED BY if given */
 	if (owned_by)
@@ -327,7 +327,7 @@ ResetSequence(Oid seq_relid)
 	/*
 	 * Insert the modified tuple into the new storage file.
 	 */
-	fill_seq_with_data(seq_rel, tuple);
+	fill_seq_with_data(seq_rel, tuple, InvalidBuffer);
 
 	/* Clear local cache so that we don't think we have cached numbers */
 	/* Note that we do not change the currval() state */
@@ -340,18 +340,21 @@ ResetSequence(Oid seq_relid)
  * Initialize a sequence's relation with the specified tuple as content
  */
 static void
-fill_seq_with_data(Relation rel, HeapTuple tuple)
+fill_seq_with_data(Relation rel, HeapTuple tuple, Buffer buf)
 {
-	Buffer		buf;
 	Page		page;
 	sequence_magic *sm;
 	OffsetNumber offnum;
+	bool lockBuffer = false;
 
 	/* Initialize first page of relation with special magic number */
 
-	buf = ReadBuffer(rel, P_NEW);
-	Assert(BufferGetBlockNumber(buf) == 0);
-
+	if (buf == InvalidBuffer)
+	{
+		buf = ReadBuffer(rel, P_NEW);
+		Assert(BufferGetBlockNumber(buf) == 0);
+		lockBuffer = true;
+	}
 	page = BufferGetPage(buf);
 
 	PageInit(page, BufferGetPageSize(buf), sizeof(sequence_magic));
@@ -360,7 +363,8 @@ fill_seq_with_data(Relation rel, HeapTuple tuple)
 
 	/* Now insert sequence tuple */
 
-	LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
+	if (lockBuffer)
+		LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
 
 	/*
 	 * Since VACUUM does not process sequences, we have to force the tuple to
@@ -410,7 +414,8 @@ fill_seq_with_data(Relation rel, HeapTuple tuple)
 
 	END_CRIT_SECTION();
 
-	UnlockReleaseBuffer(buf);
+	if (lockBuffer)
+		UnlockReleaseBuffer(buf);
 }
 
 /*
@@ -502,7 +507,7 @@ AlterSequence(ParseState *pstate, AlterSeqStmt *stmt)
 		/*
 		 * Insert the modified tuple into the new storage file.
 		 */
-		fill_seq_with_data(seqrel, newdatatuple);
+		fill_seq_with_data(seqrel, newdatatuple, InvalidBuffer);
 	}
 
 	/* process OWNED BY if given */
@@ -1178,6 +1183,17 @@ read_seq_tuple(Relation rel, Buffer *buf, HeapTuple seqdatatuple)
 	LockBuffer(*buf, BUFFER_LOCK_EXCLUSIVE);
 
 	page = BufferGetPage(*buf);
+	if (GlobalTempRelationPageIsNotInitialized(rel, page))
+	{
+		/* Initialize sequence for global temporary tables */
+		Datum		value[SEQ_COL_LASTCOL] = {0};
+		bool		null[SEQ_COL_LASTCOL] = {false};
+		HeapTuple tuple;
+		value[SEQ_COL_LASTVAL-1] = Int64GetDatumFast(1); /* start sequence with 1 */
+		tuple = heap_form_tuple(RelationGetDescr(rel), value, null);
+		fill_seq_with_data(rel, tuple, *buf);
+	}
+
 	sm = (sequence_magic *) PageGetSpecialPointer(page);
 
 	if (sm->magic != SEQ_MAGIC)
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index fb2be10..a31f775 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -586,7 +586,7 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
 	 * Check consistency of arguments
 	 */
 	if (stmt->oncommit != ONCOMMIT_NOOP
-		&& stmt->relation->relpersistence != RELPERSISTENCE_TEMP)
+		&& !IsLocalRelpersistence(stmt->relation->relpersistence))
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
 				 errmsg("ON COMMIT can only be used on temporary tables")));
@@ -1772,7 +1772,8 @@ ExecuteTruncateGuts(List *explicit_rels, List *relids, List *relids_logged,
 		 * table or the current physical file to be thrown away anyway.
 		 */
 		if (rel->rd_createSubid == mySubid ||
-			rel->rd_newRelfilenodeSubid == mySubid)
+			rel->rd_newRelfilenodeSubid == mySubid ||
+			rel->rd_rel->relpersistence == RELPERSISTENCE_SESSION)
 		{
 			/* Immediate, non-rollbackable truncation is OK */
 			heap_truncate_one_rel(rel);
@@ -7678,6 +7679,12 @@ ATAddForeignKeyConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
 						(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
 						 errmsg("constraints on unlogged tables may reference only permanent or unlogged tables")));
 			break;
+		case RELPERSISTENCE_SESSION:
+			if (pkrel->rd_rel->relpersistence != RELPERSISTENCE_SESSION)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+						 errmsg("constraints on session tables may reference only session tables")));
+			break;
 		case RELPERSISTENCE_TEMP:
 			if (pkrel->rd_rel->relpersistence != RELPERSISTENCE_TEMP)
 				ereport(ERROR,
@@ -14082,6 +14089,13 @@ ATPrepChangePersistence(Relation rel, bool toLogged)
 							RelationGetRelationName(rel)),
 					 errtable(rel)));
 			break;
+		case RELPERSISTENCE_SESSION:
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+					 errmsg("cannot change logged status of session table \"%s\"",
+							RelationGetRelationName(rel)),
+					 errtable(rel)));
+			break;
 		case RELPERSISTENCE_PERMANENT:
 			if (toLogged)
 				/* nothing to do */
@@ -14569,14 +14583,7 @@ PreCommit_on_commit_actions(void)
 				/* Do nothing (there shouldn't be such entries, actually) */
 				break;
 			case ONCOMMIT_DELETE_ROWS:
-
-				/*
-				 * If this transaction hasn't accessed any temporary
-				 * relations, we can skip truncating ON COMMIT DELETE ROWS
-				 * tables, as they must still be empty.
-				 */
-				if ((MyXactFlags & XACT_FLAGS_ACCESSEDTEMPNAMESPACE))
-					oids_to_truncate = lappend_oid(oids_to_truncate, oc->relid);
+				oids_to_truncate = lappend_oid(oids_to_truncate, oc->relid);
 				break;
 			case ONCOMMIT_DROP:
 				oids_to_drop = lappend_oid(oids_to_drop, oc->relid);
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index c97bb36..f9b2000 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -3265,20 +3265,11 @@ OptTemp:	TEMPORARY					{ $$ = RELPERSISTENCE_TEMP; }
 			| TEMP						{ $$ = RELPERSISTENCE_TEMP; }
 			| LOCAL TEMPORARY			{ $$ = RELPERSISTENCE_TEMP; }
 			| LOCAL TEMP				{ $$ = RELPERSISTENCE_TEMP; }
-			| GLOBAL TEMPORARY
-				{
-					ereport(WARNING,
-							(errmsg("GLOBAL is deprecated in temporary table creation"),
-							 parser_errposition(@1)));
-					$$ = RELPERSISTENCE_TEMP;
-				}
-			| GLOBAL TEMP
-				{
-					ereport(WARNING,
-							(errmsg("GLOBAL is deprecated in temporary table creation"),
-							 parser_errposition(@1)));
-					$$ = RELPERSISTENCE_TEMP;
-				}
+			| GLOBAL TEMPORARY          { $$ = RELPERSISTENCE_SESSION; }
+			| GLOBAL TEMP               { $$ = RELPERSISTENCE_SESSION; }
+			| SESSION                   { $$ = RELPERSISTENCE_SESSION; }
+			| SESSION TEMPORARY         { $$ = RELPERSISTENCE_SESSION; }
+			| SESSION TEMP              { $$ = RELPERSISTENCE_SESSION; }
 			| UNLOGGED					{ $$ = RELPERSISTENCE_UNLOGGED; }
 			| /*EMPTY*/					{ $$ = RELPERSISTENCE_PERMANENT; }
 		;
diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c
index 6e5768c..ea6989b 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -437,6 +437,14 @@ generateSerialExtraStmts(CreateStmtContext *cxt, ColumnDef *column,
 	seqstmt->options = seqoptions;
 
 	/*
+	 * Why we should not always use persistence of parent table?
+	 * Although it is prohibited to have unlogged sequences,
+	 * unlogged tables with SERIAL fields are accepted!
+	 */
+	if (cxt->relation->relpersistence != RELPERSISTENCE_UNLOGGED)
+		seqstmt->sequence->relpersistence = cxt->relation->relpersistence;
+
+	/*
 	 * If a sequence data type was specified, add it to the options.  Prepend
 	 * to the list rather than append; in case a user supplied their own AS
 	 * clause, the "redundant options" error will point to their occurrence,
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index 073f313..3383c35 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -2069,7 +2069,7 @@ do_autovacuum(void)
 		 * Check if it is a temp table (presumably, of some other backend's).
 		 * We cannot safely process other backends' temp tables.
 		 */
-		if (classForm->relpersistence == RELPERSISTENCE_TEMP)
+		if (IsLocalRelpersistence(classForm->relpersistence))
 		{
 			/*
 			 * We just ignore it if the owning backend is still active and
@@ -2154,7 +2154,7 @@ do_autovacuum(void)
 		/*
 		 * We cannot safely process other backends' temp tables, so skip 'em.
 		 */
-		if (classForm->relpersistence == RELPERSISTENCE_TEMP)
+		if (IsLocalRelpersistence(classForm->relpersistence))
 			continue;
 
 		relid = classForm->oid;
diff --git a/src/backend/storage/smgr/md.c b/src/backend/storage/smgr/md.c
index 07f3c93..5db79ec 100644
--- a/src/backend/storage/smgr/md.c
+++ b/src/backend/storage/smgr/md.c
@@ -33,6 +33,7 @@
 #include "postmaster/bgwriter.h"
 #include "storage/fd.h"
 #include "storage/bufmgr.h"
+#include "storage/ipc.h"
 #include "storage/md.h"
 #include "storage/relfilenode.h"
 #include "storage/smgr.h"
@@ -87,6 +88,18 @@ typedef struct _MdfdVec
 
 static MemoryContext MdCxt;		/* context for all MdfdVec objects */
 
+/*
+ * Structure used to collect information created by this backend.
+ * Data of this related should be deleted on backend exit.
+ */
+typedef struct SessionRelation
+{
+	RelFileNodeBackend rnode;
+	struct SessionRelation* next;
+} SessionRelation;
+
+
+static SessionRelation* SessionRelations;
 
 /* Populate a file tag describing an md.c segment file. */
 #define INIT_MD_FILETAG(a,xx_rnode,xx_forknum,xx_segno) \
@@ -152,6 +165,45 @@ mdinit(void)
 								  ALLOCSET_DEFAULT_SIZES);
 }
 
+
+/*
+ * Delete all data of session relations and remove their pages from shared buffers.
+ * This function is called on backend exit.
+ */
+static void
+TruncateSessionRelations(int code, Datum arg)
+{
+	SessionRelation* rel;
+	for (rel = SessionRelations; rel != NULL; rel = rel->next)
+	{
+		/* Delete relation files */
+		mdunlink(rel->rnode, InvalidForkNumber, false);
+	}
+}
+
+/*
+ * Maintain information about session relations accessed by this backend.
+ * This list is needed to perform cleanup on backend exit.
+ * Session relation is linked in this list when this relation is created or opened and file doesn't exist.
+ * Such procedure guarantee that each relation is linked into list only once.
+ */
+static void
+RegisterSessionRelation(SMgrRelation reln)
+{
+	SessionRelation* rel = (SessionRelation*)MemoryContextAlloc(TopMemoryContext, sizeof(SessionRelation));
+
+	/*
+	 * Perform session relation cleanup on backend exit. We are using shared memory hook, because
+	 * cleanup should be performed before backend is disconnected from shared memory.
+	 */
+	if (SessionRelations == NULL)
+		on_shmem_exit(TruncateSessionRelations, 0);
+
+	rel->rnode = reln->smgr_rnode;
+	rel->next = SessionRelations;
+	SessionRelations = rel;
+}
+
 /*
  *	mdexists() -- Does the physical file exist?
  *
@@ -218,6 +270,8 @@ mdcreate(SMgrRelation reln, ForkNumber forkNum, bool isRedo)
 					 errmsg("could not create file \"%s\": %m", path)));
 		}
 	}
+	if (RelFileNodeBackendIsGlobalTemp(reln->smgr_rnode))
+		RegisterSessionRelation(reln);
 
 	pfree(path);
 
@@ -465,6 +519,19 @@ mdopenfork(SMgrRelation reln, ForkNumber forknum, int behavior)
 
 	if (fd < 0)
 	{
+		/*
+		 * In case of session relation access, there may be no yet files of this relation for this backend.
+		 * If so, then create file and register session relation for truncation on backend exit.
+		 */
+		if (RelFileNodeBackendIsGlobalTemp(reln->smgr_rnode))
+		{
+			fd = PathNameOpenFile(path, O_RDWR | PG_BINARY | O_CREAT);
+			if (fd >= 0)
+			{
+				RegisterSessionRelation(reln);
+				goto NewSegment;
+			}
+		}
 		if ((behavior & EXTENSION_RETURN_NULL) &&
 			FILE_POSSIBLY_DELETED(errno))
 		{
@@ -476,6 +543,7 @@ mdopenfork(SMgrRelation reln, ForkNumber forknum, int behavior)
 				 errmsg("could not open file \"%s\": %m", path)));
 	}
 
+  NewSegment:
 	pfree(path);
 
 	_fdvec_resize(reln, forknum, 1);
@@ -652,8 +720,13 @@ mdread(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
 		 * complaining.  This allows, for example, the case of trying to
 		 * update a block that was later truncated away.
 		 */
-		if (zero_damaged_pages || InRecovery)
+		if (zero_damaged_pages || InRecovery || RelFileNodeBackendIsGlobalTemp(reln->smgr_rnode))
+		{
 			MemSet(buffer, 0, BLCKSZ);
+			/* In case of session relation we need to write zero page to provide correct result of subsequent mdnblocks */
+			if (RelFileNodeBackendIsGlobalTemp(reln->smgr_rnode))
+				mdwrite(reln, forknum, blocknum, buffer, true);
+		}
 		else
 			ereport(ERROR,
 					(errcode(ERRCODE_DATA_CORRUPTED),
@@ -738,12 +811,18 @@ mdwrite(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
 BlockNumber
 mdnblocks(SMgrRelation reln, ForkNumber forknum)
 {
-	MdfdVec    *v = mdopenfork(reln, forknum, EXTENSION_FAIL);
+	/*
+	 * If we access session relation, there may be no files yet of this relation for this backend.
+	 * Pass EXTENSION_RETURN_NULL to make mdopen return NULL in this case instead of reporting error.
+	 */
+	MdfdVec    *v = mdopenfork(reln, forknum, RelFileNodeBackendIsGlobalTemp(reln->smgr_rnode)
+							   ? EXTENSION_RETURN_NULL : EXTENSION_FAIL);
 	BlockNumber nblocks;
 	BlockNumber segno = 0;
 
 	/* mdopen has opened the first segment */
-	Assert(reln->md_num_open_segs[forknum] > 0);
+	if (reln->md_num_open_segs[forknum] == 0)
+		return 0;
 
 	/*
 	 * Start from the last open segments, to avoid redundant seeks.  We have
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index a87e721..2401361 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -994,6 +994,9 @@ pg_relation_filepath(PG_FUNCTION_ARGS)
 	/* Determine owning backend. */
 	switch (relform->relpersistence)
 	{
+		case RELPERSISTENCE_SESSION:
+			backend = BackendIdForSessionRelations();
+			break;
 		case RELPERSISTENCE_UNLOGGED:
 		case RELPERSISTENCE_PERMANENT:
 			backend = InvalidBackendId;
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index 2488607..86e8fca 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -1098,6 +1098,10 @@ RelationBuildDesc(Oid targetRelId, bool insertIt)
 	relation->rd_newRelfilenodeSubid = InvalidSubTransactionId;
 	switch (relation->rd_rel->relpersistence)
 	{
+		case RELPERSISTENCE_SESSION:
+			relation->rd_backend = BackendIdForSessionRelations();
+			relation->rd_islocaltemp = false;
+			break;
 		case RELPERSISTENCE_UNLOGGED:
 		case RELPERSISTENCE_PERMANENT:
 			relation->rd_backend = InvalidBackendId;
@@ -3301,6 +3305,10 @@ RelationBuildLocalRelation(const char *relname,
 	rel->rd_rel->relpersistence = relpersistence;
 	switch (relpersistence)
 	{
+		case RELPERSISTENCE_SESSION:
+			rel->rd_backend = BackendIdForSessionRelations();
+			rel->rd_islocaltemp = false;
+			break;
 		case RELPERSISTENCE_UNLOGGED:
 		case RELPERSISTENCE_PERMANENT:
 			rel->rd_backend = InvalidBackendId;
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 0cc9ede..1dff0c8 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -15593,8 +15593,8 @@ dumpTableSchema(Archive *fout, TableInfo *tbinfo)
 											 tbinfo->dobj.catId.oid, false);
 
 		appendPQExpBuffer(q, "CREATE %s%s %s",
-						  tbinfo->relpersistence == RELPERSISTENCE_UNLOGGED ?
-						  "UNLOGGED " : "",
+						  tbinfo->relpersistence == RELPERSISTENCE_UNLOGGED ? "UNLOGGED "
+						  : tbinfo->relpersistence == RELPERSISTENCE_SESSION ? "SESSION " : "",
 						  reltypename,
 						  qualrelname);
 
diff --git a/src/common/relpath.c b/src/common/relpath.c
index 62b9553..cef99d2 100644
--- a/src/common/relpath.c
+++ b/src/common/relpath.c
@@ -166,7 +166,18 @@ GetRelationPath(Oid dbNode, Oid spcNode, Oid relNode,
 		}
 		else
 		{
-			if (forkNumber != MAIN_FORKNUM)
+			/*
+			 * Session relations are distinguished from local temp relations by adding
+			 * SessionRelFirstBackendId offset to backendId.
+			 * These is no need to separate them at file system level, so just subtract SessionRelFirstBackendId
+			 * to avoid too long file names.
+			 * Segments of session relations have the same prefix (t%d_) as local temporary relations
+			 * to make it possible to cleanup them in the same way as local temporary relation files.
+			 */
+			 if (backendId >= SessionRelFirstBackendId)
+				 backendId -= SessionRelFirstBackendId;
+
+			 if (forkNumber != MAIN_FORKNUM)
 				path = psprintf("base/%u/t%d_%u_%s",
 								dbNode, backendId, relNode,
 								forkNames[forkNumber]);
diff --git a/src/include/catalog/pg_class.h b/src/include/catalog/pg_class.h
index 090b6ba..6a39663 100644
--- a/src/include/catalog/pg_class.h
+++ b/src/include/catalog/pg_class.h
@@ -165,6 +165,7 @@ typedef FormData_pg_class *Form_pg_class;
 #define		  RELPERSISTENCE_PERMANENT	'p' /* regular table */
 #define		  RELPERSISTENCE_UNLOGGED	'u' /* unlogged permanent table */
 #define		  RELPERSISTENCE_TEMP		't' /* temporary table */
+#define		  RELPERSISTENCE_SESSION	's' /* session table */
 
 /* default selection for replica identity (primary key or nothing) */
 #define		  REPLICA_IDENTITY_DEFAULT	'd'
diff --git a/src/include/storage/backendid.h b/src/include/storage/backendid.h
index 70ef8eb..f226e7c 100644
--- a/src/include/storage/backendid.h
+++ b/src/include/storage/backendid.h
@@ -22,6 +22,13 @@ typedef int BackendId;			/* unique currently active backend identifier */
 
 #define InvalidBackendId		(-1)
 
+/*
+ * We need to distinguish local and global temporary relations by RelFileNodeBackend.
+ * The least invasive change is to add some special bias value to backend id (since 
+ * maximal number of backed is limited by MaxBackends).
+ */
+#define SessionRelFirstBackendId (0x40000000)
+
 extern PGDLLIMPORT BackendId MyBackendId;	/* backend id of this backend */
 
 /* backend id of our parallel session leader, or InvalidBackendId if none */
@@ -34,4 +41,10 @@ extern PGDLLIMPORT BackendId ParallelMasterBackendId;
 #define BackendIdForTempRelations() \
 	(ParallelMasterBackendId == InvalidBackendId ? MyBackendId : ParallelMasterBackendId)
 
+
+#define BackendIdForSessionRelations() \
+	(BackendIdForTempRelations() + SessionRelFirstBackendId)
+
+#define IsSessionRelationBackendId(id) ((id) >= SessionRelFirstBackendId)
+
 #endif							/* BACKENDID_H */
diff --git a/src/include/storage/bufpage.h b/src/include/storage/bufpage.h
index 4ef6d8d..bac7a31 100644
--- a/src/include/storage/bufpage.h
+++ b/src/include/storage/bufpage.h
@@ -229,6 +229,13 @@ typedef PageHeaderData *PageHeader;
 #define PageIsNew(page) (((PageHeader) (page))->pd_upper == 0)
 
 /*
+ * Page of temporary relation is not initialized
+ */
+#define GlobalTempRelationPageIsNotInitialized(rel, page) \
+	((rel)->rd_rel->relpersistence == RELPERSISTENCE_SESSION && PageIsNew(page))
+
+
+/*
  * PageGetItemId
  *		Returns an item identifier of a page.
  */
diff --git a/src/include/storage/relfilenode.h b/src/include/storage/relfilenode.h
index 586500a..20aec72 100644
--- a/src/include/storage/relfilenode.h
+++ b/src/include/storage/relfilenode.h
@@ -75,10 +75,25 @@ typedef struct RelFileNodeBackend
 	BackendId	backend;
 } RelFileNodeBackend;
 
+/*
+ * Check whether it is local or global temporary relation, which data belongs only to one backend.
+ */
 #define RelFileNodeBackendIsTemp(rnode) \
 	((rnode).backend != InvalidBackendId)
 
 /*
+ * Check whether it is global temporary relation which metadata is shared by all sessions,
+ * but data is private for the current session.
+ */
+#define RelFileNodeBackendIsGlobalTemp(rnode) IsSessionRelationBackendId((rnode).backend)
+
+/*
+ * Check whether it is local temporary relation which exists only in this backend.
+ */
+#define RelFileNodeBackendIsLocalTemp(rnode) \
+	(RelFileNodeBackendIsTemp(rnode) && !RelFileNodeBackendIsGlobalTemp(rnode))
+
+/*
  * Note: RelFileNodeEquals and RelFileNodeBackendEquals compare relNode first
  * since that is most likely to be different in two unequal RelFileNodes.  It
  * is probably redundant to compare spcNode if the other fields are found equal,
diff --git a/src/include/utils/rel.h b/src/include/utils/rel.h
index b0fe19e..dfa2044 100644
--- a/src/include/utils/rel.h
+++ b/src/include/utils/rel.h
@@ -328,6 +328,17 @@ typedef struct StdRdOptions
 	((relation)->rd_options ? \
 	 ((StdRdOptions *) (relation)->rd_options)->parallel_workers : (defaultpw))
 
+/*
+ * Relation persistence is either TEMP either SESSION
+ */
+#define IsLocalRelpersistence(relpersistence) \
+	((relpersistence) == RELPERSISTENCE_TEMP || (relpersistence) == RELPERSISTENCE_SESSION)
+
+/*
+ * Relation is either global either local temp table
+ */
+#define RelationHasSessionScope(relation) \
+	IsLocalRelpersistence(((relation)->rd_rel->relpersistence))
 
 /*
  * ViewOptions
@@ -524,7 +535,7 @@ typedef struct ViewOptions
  *		True if relation's pages are stored in local buffers.
  */
 #define RelationUsesLocalBuffers(relation) \
-	((relation)->rd_rel->relpersistence == RELPERSISTENCE_TEMP)
+	RelationHasSessionScope(relation)
 
 /*
  * RELATION_IS_LOCAL
diff --git a/src/test/isolation/expected/inherit-global-temp.out b/src/test/isolation/expected/inherit-global-temp.out
new file mode 100644
index 0000000..6114f8c
--- /dev/null
+++ b/src/test/isolation/expected/inherit-global-temp.out
@@ -0,0 +1,218 @@
+Parsed test spec with 2 sessions
+
+starting permutation: s1_insert_p s1_insert_c s2_insert_c s1_select_p s1_select_c s2_select_p s2_select_c
+step s1_insert_p: INSERT INTO inh_global_parent VALUES (1), (2);
+step s1_insert_c: INSERT INTO inh_global_temp_child_s1 VALUES (3), (4);
+step s2_insert_c: INSERT INTO inh_global_temp_child_s2 VALUES (5), (6);
+step s1_select_p: SELECT a FROM inh_global_parent;
+a              
+
+1              
+2              
+3              
+4              
+step s1_select_c: SELECT a FROM inh_global_temp_child_s1;
+a              
+
+3              
+4              
+step s2_select_p: SELECT a FROM inh_global_parent;
+a              
+
+1              
+2              
+5              
+6              
+step s2_select_c: SELECT a FROM inh_global_temp_child_s2;
+a              
+
+5              
+6              
+
+starting permutation: s1_insert_p s1_insert_c s2_insert_c s1_update_p s1_update_c s1_select_p s1_select_c s2_select_p s2_select_c
+step s1_insert_p: INSERT INTO inh_global_parent VALUES (1), (2);
+step s1_insert_c: INSERT INTO inh_global_temp_child_s1 VALUES (3), (4);
+step s2_insert_c: INSERT INTO inh_global_temp_child_s2 VALUES (5), (6);
+step s1_update_p: UPDATE inh_global_parent SET a = 11 WHERE a = 1;
+step s1_update_c: UPDATE inh_global_parent SET a = 13 WHERE a IN (3, 5);
+step s1_select_p: SELECT a FROM inh_global_parent;
+a              
+
+2              
+11             
+4              
+13             
+step s1_select_c: SELECT a FROM inh_global_temp_child_s1;
+a              
+
+4              
+13             
+step s2_select_p: SELECT a FROM inh_global_parent;
+a              
+
+2              
+11             
+5              
+6              
+step s2_select_c: SELECT a FROM inh_global_temp_child_s2;
+a              
+
+5              
+6              
+
+starting permutation: s1_insert_p s1_insert_c s2_insert_c s2_update_c s1_select_p s1_select_c s2_select_p s2_select_c
+step s1_insert_p: INSERT INTO inh_global_parent VALUES (1), (2);
+step s1_insert_c: INSERT INTO inh_global_temp_child_s1 VALUES (3), (4);
+step s2_insert_c: INSERT INTO inh_global_temp_child_s2 VALUES (5), (6);
+step s2_update_c: UPDATE inh_global_parent SET a = 15 WHERE a IN (3, 5);
+step s1_select_p: SELECT a FROM inh_global_parent;
+a              
+
+1              
+2              
+3              
+4              
+step s1_select_c: SELECT a FROM inh_global_temp_child_s1;
+a              
+
+3              
+4              
+step s2_select_p: SELECT a FROM inh_global_parent;
+a              
+
+1              
+2              
+6              
+15             
+step s2_select_c: SELECT a FROM inh_global_temp_child_s2;
+a              
+
+6              
+15             
+
+starting permutation: s1_insert_p s1_insert_c s2_insert_c s1_delete_p s1_delete_c s1_select_p s1_select_c s2_select_p s2_select_c
+step s1_insert_p: INSERT INTO inh_global_parent VALUES (1), (2);
+step s1_insert_c: INSERT INTO inh_global_temp_child_s1 VALUES (3), (4);
+step s2_insert_c: INSERT INTO inh_global_temp_child_s2 VALUES (5), (6);
+step s1_delete_p: DELETE FROM inh_global_parent WHERE a = 2;
+step s1_delete_c: DELETE FROM inh_global_parent WHERE a IN (4, 6);
+step s1_select_p: SELECT a FROM inh_global_parent;
+a              
+
+1              
+3              
+step s1_select_c: SELECT a FROM inh_global_temp_child_s1;
+a              
+
+3              
+step s2_select_p: SELECT a FROM inh_global_parent;
+a              
+
+1              
+5              
+6              
+step s2_select_c: SELECT a FROM inh_global_temp_child_s2;
+a              
+
+5              
+6              
+
+starting permutation: s1_insert_p s1_insert_c s2_insert_c s2_delete_c s1_select_p s1_select_c s2_select_p s2_select_c
+step s1_insert_p: INSERT INTO inh_global_parent VALUES (1), (2);
+step s1_insert_c: INSERT INTO inh_global_temp_child_s1 VALUES (3), (4);
+step s2_insert_c: INSERT INTO inh_global_temp_child_s2 VALUES (5), (6);
+step s2_delete_c: DELETE FROM inh_global_parent WHERE a IN (4, 6);
+step s1_select_p: SELECT a FROM inh_global_parent;
+a              
+
+1              
+2              
+3              
+4              
+step s1_select_c: SELECT a FROM inh_global_temp_child_s1;
+a              
+
+3              
+4              
+step s2_select_p: SELECT a FROM inh_global_parent;
+a              
+
+1              
+2              
+5              
+step s2_select_c: SELECT a FROM inh_global_temp_child_s2;
+a              
+
+5              
+
+starting permutation: s1_insert_p s1_insert_c s2_insert_c s1_truncate_p s1_select_p s1_select_c s2_select_p s2_select_c
+step s1_insert_p: INSERT INTO inh_global_parent VALUES (1), (2);
+step s1_insert_c: INSERT INTO inh_global_temp_child_s1 VALUES (3), (4);
+step s2_insert_c: INSERT INTO inh_global_temp_child_s2 VALUES (5), (6);
+step s1_truncate_p: TRUNCATE inh_global_parent;
+step s1_select_p: SELECT a FROM inh_global_parent;
+a              
+
+step s1_select_c: SELECT a FROM inh_global_temp_child_s1;
+a              
+
+step s2_select_p: SELECT a FROM inh_global_parent;
+a              
+
+5              
+6              
+step s2_select_c: SELECT a FROM inh_global_temp_child_s2;
+a              
+
+5              
+6              
+
+starting permutation: s1_insert_p s1_insert_c s2_insert_c s2_truncate_p s1_select_p s1_select_c s2_select_p s2_select_c
+step s1_insert_p: INSERT INTO inh_global_parent VALUES (1), (2);
+step s1_insert_c: INSERT INTO inh_global_temp_child_s1 VALUES (3), (4);
+step s2_insert_c: INSERT INTO inh_global_temp_child_s2 VALUES (5), (6);
+step s2_truncate_p: TRUNCATE inh_global_parent;
+step s1_select_p: SELECT a FROM inh_global_parent;
+a              
+
+3              
+4              
+step s1_select_c: SELECT a FROM inh_global_temp_child_s1;
+a              
+
+3              
+4              
+step s2_select_p: SELECT a FROM inh_global_parent;
+a              
+
+step s2_select_c: SELECT a FROM inh_global_temp_child_s2;
+a              
+
+
+starting permutation: s1_insert_p s1_insert_c s2_insert_c s1_begin s1_truncate_p s2_select_p s1_commit
+step s1_insert_p: INSERT INTO inh_global_parent VALUES (1), (2);
+step s1_insert_c: INSERT INTO inh_global_temp_child_s1 VALUES (3), (4);
+step s2_insert_c: INSERT INTO inh_global_temp_child_s2 VALUES (5), (6);
+step s1_begin: BEGIN;
+step s1_truncate_p: TRUNCATE inh_global_parent;
+step s2_select_p: SELECT a FROM inh_global_parent; <waiting ...>
+step s1_commit: COMMIT;
+step s2_select_p: <... completed>
+a              
+
+5              
+6              
+
+starting permutation: s1_insert_p s1_insert_c s2_insert_c s1_begin s1_truncate_p s2_select_c s1_commit
+step s1_insert_p: INSERT INTO inh_global_parent VALUES (1), (2);
+step s1_insert_c: INSERT INTO inh_global_temp_child_s1 VALUES (3), (4);
+step s2_insert_c: INSERT INTO inh_global_temp_child_s2 VALUES (5), (6);
+step s1_begin: BEGIN;
+step s1_truncate_p: TRUNCATE inh_global_parent;
+step s2_select_c: SELECT a FROM inh_global_temp_child_s2; <waiting ...>
+step s1_commit: COMMIT;
+step s2_select_c: <... completed>
+a              
+
+5              
+6              
diff --git a/src/test/isolation/isolation_schedule b/src/test/isolation/isolation_schedule
index 69ae227..95919f8 100644
--- a/src/test/isolation/isolation_schedule
+++ b/src/test/isolation/isolation_schedule
@@ -87,3 +87,4 @@ test: plpgsql-toast
 test: truncate-conflict
 test: serializable-parallel
 test: serializable-parallel-2
+test: inherit-global-temp
diff --git a/src/test/isolation/specs/inherit-global-temp.spec b/src/test/isolation/specs/inherit-global-temp.spec
new file mode 100644
index 0000000..5e95dd6
--- /dev/null
+++ b/src/test/isolation/specs/inherit-global-temp.spec
@@ -0,0 +1,73 @@
+# This is a copy of the inherit-temp test with little changes for global temporary tables.
+#
+
+setup
+{
+  CREATE TABLE inh_global_parent (a int);
+}
+
+teardown
+{
+  DROP TABLE inh_global_parent;
+}
+
+# Session 1 executes actions which act directly on both the parent and
+# its child.  Abbreviation "c" is used for queries working on the child
+# and "p" on the parent.
+session "s1"
+setup
+{
+  CREATE GLOBAL TEMPORARY TABLE inh_global_temp_child_s1 () INHERITS (inh_global_parent);
+}
+step "s1_begin" { BEGIN; }
+step "s1_truncate_p" { TRUNCATE inh_global_parent; }
+step "s1_select_p" { SELECT a FROM inh_global_parent; }
+step "s1_select_c" { SELECT a FROM inh_global_temp_child_s1; }
+step "s1_insert_p" { INSERT INTO inh_global_parent VALUES (1), (2); }
+step "s1_insert_c" { INSERT INTO inh_global_temp_child_s1 VALUES (3), (4); }
+step "s1_update_p" { UPDATE inh_global_parent SET a = 11 WHERE a = 1; }
+step "s1_update_c" { UPDATE inh_global_parent SET a = 13 WHERE a IN (3, 5); }
+step "s1_delete_p" { DELETE FROM inh_global_parent WHERE a = 2; }
+step "s1_delete_c" { DELETE FROM inh_global_parent WHERE a IN (4, 6); }
+step "s1_commit" { COMMIT; }
+teardown
+{
+  DROP TABLE inh_global_temp_child_s1;
+}
+
+# Session 2 executes actions on the parent which act only on the child.
+session "s2"
+setup
+{
+  CREATE GLOBAL TEMPORARY TABLE inh_global_temp_child_s2 () INHERITS (inh_global_parent);
+}
+step "s2_truncate_p" { TRUNCATE inh_global_parent; }
+step "s2_select_p" { SELECT a FROM inh_global_parent; }
+step "s2_select_c" { SELECT a FROM inh_global_temp_child_s2; }
+step "s2_insert_c" { INSERT INTO inh_global_temp_child_s2 VALUES (5), (6); }
+step "s2_update_c" { UPDATE inh_global_parent SET a = 15 WHERE a IN (3, 5); }
+step "s2_delete_c" { DELETE FROM inh_global_parent WHERE a IN (4, 6); }
+teardown
+{
+  DROP TABLE inh_global_temp_child_s2;
+}
+
+# Check INSERT behavior across sessions
+permutation "s1_insert_p" "s1_insert_c" "s2_insert_c" "s1_select_p" "s1_select_c" "s2_select_p" "s2_select_c"
+
+# Check UPDATE behavior across sessions
+permutation "s1_insert_p" "s1_insert_c" "s2_insert_c" "s1_update_p" "s1_update_c" "s1_select_p" "s1_select_c" "s2_select_p" "s2_select_c"
+permutation "s1_insert_p" "s1_insert_c" "s2_insert_c" "s2_update_c" "s1_select_p" "s1_select_c" "s2_select_p" "s2_select_c"
+
+# Check DELETE behavior across sessions
+permutation "s1_insert_p" "s1_insert_c" "s2_insert_c" "s1_delete_p" "s1_delete_c" "s1_select_p" "s1_select_c" "s2_select_p" "s2_select_c"
+permutation "s1_insert_p" "s1_insert_c" "s2_insert_c" "s2_delete_c" "s1_select_p" "s1_select_c" "s2_select_p" "s2_select_c"
+
+# Check TRUNCATE behavior across sessions
+permutation "s1_insert_p" "s1_insert_c" "s2_insert_c" "s1_truncate_p" "s1_select_p" "s1_select_c" "s2_select_p" "s2_select_c"
+permutation "s1_insert_p" "s1_insert_c" "s2_insert_c" "s2_truncate_p" "s1_select_p" "s1_select_c" "s2_select_p" "s2_select_c"
+
+# TRUNCATE on a parent tree does not block access to temporary child relation
+# of another session, and blocks when scanning the parent.
+permutation "s1_insert_p" "s1_insert_c" "s2_insert_c" "s1_begin" "s1_truncate_p" "s2_select_p" "s1_commit"
+permutation "s1_insert_p" "s1_insert_c" "s2_insert_c" "s1_begin" "s1_truncate_p" "s2_select_c" "s1_commit"
diff --git a/src/test/regress/expected/global_temp.out b/src/test/regress/expected/global_temp.out
new file mode 100644
index 0000000..ae1adb6
--- /dev/null
+++ b/src/test/regress/expected/global_temp.out
@@ -0,0 +1,247 @@
+--
+-- GLOBAL TEMP
+-- Test global temp relations
+--
+-- Test ON COMMIT DELETE ROWS
+CREATE GLOBAL TEMP TABLE global_temptest(col int) ON COMMIT DELETE ROWS;
+BEGIN;
+INSERT INTO global_temptest VALUES (1);
+INSERT INTO global_temptest VALUES (2);
+SELECT * FROM global_temptest;
+ col 
+-----
+   1
+   2
+(2 rows)
+
+COMMIT;
+SELECT * FROM global_temptest;
+ col 
+-----
+(0 rows)
+
+DROP TABLE global_temptest;
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temptest(col) ON COMMIT DELETE ROWS AS SELECT 1;
+SELECT * FROM global_temptest;
+ col 
+-----
+   1
+(1 row)
+
+COMMIT;
+SELECT * FROM global_temptest;
+ col 
+-----
+(0 rows)
+
+DROP TABLE global_temptest;
+-- Test foreign keys
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temptest1(col int PRIMARY KEY);
+CREATE GLOBAL TEMP TABLE global_temptest2(col int REFERENCES global_temptest1)
+  ON COMMIT DELETE ROWS;
+INSERT INTO global_temptest1 VALUES (1);
+INSERT INTO global_temptest2 VALUES (1);
+COMMIT;
+SELECT * FROM global_temptest1;
+ col 
+-----
+   1
+(1 row)
+
+SELECT * FROM global_temptest2;
+ col 
+-----
+(0 rows)
+
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temptest3(col int PRIMARY KEY) ON COMMIT DELETE ROWS;
+CREATE GLOBAL TEMP TABLE global_temptest4(col int REFERENCES global_temptest3);
+COMMIT;
+ERROR:  unsupported ON COMMIT and foreign key combination
+DETAIL:  Table "global_temptest4" references "global_temptest3", but they do not have the same ON COMMIT setting.
+-- For partitioned temp tables, ON COMMIT actions ignore storage-less
+-- partitioned tables.
+BEGIN;
+CREATE GLOBAL TEMP TABLE temp_parted_oncommit (a int)
+  PARTITION BY LIST (a) ON COMMIT DELETE ROWS;
+CREATE GLOBAL TEMP TABLE temp_parted_oncommit_1
+  PARTITION OF temp_parted_oncommit
+  FOR VALUES IN (1) ON COMMIT DELETE ROWS;
+INSERT INTO temp_parted_oncommit VALUES (1);
+COMMIT;
+-- partitions are emptied by the previous commit
+SELECT * FROM temp_parted_oncommit;
+ a 
+---
+(0 rows)
+
+DROP TABLE temp_parted_oncommit;
+-- Using ON COMMIT DELETE on a partitioned table does not remove
+-- all rows if partitions preserve their data.
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temp_parted_oncommit_test (a int)
+  PARTITION BY LIST (a) ON COMMIT DELETE ROWS;
+CREATE GLOBAL TEMP TABLE global_temp_parted_oncommit_test1
+  PARTITION OF global_temp_parted_oncommit_test
+  FOR VALUES IN (1) ON COMMIT PRESERVE ROWS;
+INSERT INTO global_temp_parted_oncommit_test VALUES (1);
+COMMIT;
+-- Data from the remaining partition is still here as its rows are
+-- preserved.
+SELECT * FROM global_temp_parted_oncommit_test;
+ a 
+---
+ 1
+(1 row)
+
+-- two relations remain in this case.
+SELECT relname FROM pg_class WHERE relname LIKE 'global_temp_parted_oncommit_test%';
+              relname              
+-----------------------------------
+ global_temp_parted_oncommit_test
+ global_temp_parted_oncommit_test1
+(2 rows)
+
+DROP TABLE global_temp_parted_oncommit_test;
+-- Check dependencies between ON COMMIT actions with inheritance trees.
+-- Data on the parent is removed, and the child goes away.
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temp_inh_oncommit_test (a int) ON COMMIT DELETE ROWS;
+CREATE GLOBAL TEMP TABLE global_temp_inh_oncommit_test1 ()
+  INHERITS(global_temp_inh_oncommit_test) ON COMMIT PRESERVE ROWS;
+INSERT INTO global_temp_inh_oncommit_test1 VALUES (1);
+INSERT INTO global_temp_inh_oncommit_test VALUES (1);
+COMMIT;
+SELECT * FROM global_temp_inh_oncommit_test;
+ a 
+---
+ 1
+(1 row)
+
+-- two relations remain
+SELECT relname FROM pg_class WHERE relname LIKE 'global_temp_inh_oncommit_test%';
+            relname             
+--------------------------------
+ global_temp_inh_oncommit_test
+ global_temp_inh_oncommit_test1
+(2 rows)
+
+DROP TABLE global_temp_inh_oncommit_test1;
+DROP TABLE global_temp_inh_oncommit_test;
+-- Global temp table cannot inherit from temporary relation
+BEGIN;
+CREATE TEMP TABLE global_temp_table (a int) ON COMMIT DELETE ROWS;
+CREATE GLOBAL TEMP TABLE global_temp_table1 ()
+  INHERITS(global_temp_table) ON COMMIT PRESERVE ROWS;
+ERROR:  cannot inherit from temporary relation "global_temp_table"
+ROLLBACK;
+-- Temp table can inherit from global temporary relation
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temp_table (a int) ON COMMIT DELETE ROWS;
+CREATE TEMP TABLE temp_table1 ()
+  INHERITS(global_temp_table) ON COMMIT PRESERVE ROWS;
+CREATE TEMP TABLE temp_table2 ()
+  INHERITS(global_temp_table) ON COMMIT DELETE ROWS;
+INSERT INTO temp_table2 VALUES (2);
+INSERT INTO temp_table1 VALUES (1);
+INSERT INTO global_temp_table VALUES (0);
+SELECT * FROM global_temp_table;
+ a 
+---
+ 0
+ 1
+ 2
+(3 rows)
+
+COMMIT;
+SELECT * FROM global_temp_table;
+ a 
+---
+ 1
+(1 row)
+
+DROP TABLE temp_table2;
+DROP TABLE temp_table1;
+DROP TABLE global_temp_table;
+-- Global temp table can inherit from normal relation
+BEGIN;
+CREATE TABLE normal_table (a int);
+CREATE GLOBAL TEMP TABLE temp_table1 ()
+  INHERITS(normal_table) ON COMMIT PRESERVE ROWS;
+CREATE GLOBAL TEMP TABLE temp_table2 ()
+  INHERITS(normal_table) ON COMMIT DELETE ROWS;
+INSERT INTO temp_table2 VALUES (2);
+INSERT INTO temp_table1 VALUES (1);
+INSERT INTO normal_table VALUES (0);
+SELECT * FROM normal_table;
+ a 
+---
+ 0
+ 1
+ 2
+(3 rows)
+
+COMMIT;
+SELECT * FROM normal_table;
+ a 
+---
+ 0
+ 1
+(2 rows)
+
+DROP TABLE temp_table2;
+DROP TABLE temp_table1;
+DROP TABLE normal_table;
+-- Check SERIAL and BIGSERIAL pseudo-types
+CREATE GLOBAL TEMP TABLE global_temp_table ( aid BIGSERIAL, bid SERIAL );
+CREATE SEQUENCE test_sequence;
+INSERT INTO global_temp_table DEFAULT VALUES;
+INSERT INTO global_temp_table DEFAULT VALUES;
+INSERT INTO global_temp_table DEFAULT VALUES;
+SELECT * FROM global_temp_table;
+ aid | bid 
+-----+-----
+   1 |   1
+   2 |   2
+   3 |   3
+(3 rows)
+
+SELECT NEXTVAL( 'test_sequence' );
+ nextval 
+---------
+       1
+(1 row)
+
+\c
+SELECT * FROM global_temp_table;
+ aid | bid 
+-----+-----
+(0 rows)
+
+SELECT NEXTVAL( 'test_sequence' );
+ nextval 
+---------
+       2
+(1 row)
+
+INSERT INTO global_temp_table DEFAULT VALUES;
+INSERT INTO global_temp_table DEFAULT VALUES;
+INSERT INTO global_temp_table DEFAULT VALUES;
+SELECT * FROM global_temp_table;
+ aid | bid 
+-----+-----
+   1 |   1
+   2 |   2
+   3 |   3
+(3 rows)
+
+SELECT NEXTVAL( 'test_sequence' );
+ nextval 
+---------
+       3
+(1 row)
+
+DROP TABLE global_temp_table;
+DROP SEQUENCE test_sequence;
diff --git a/src/test/regress/expected/session_table.out b/src/test/regress/expected/session_table.out
new file mode 100644
index 0000000..1b9b3f4
--- /dev/null
+++ b/src/test/regress/expected/session_table.out
@@ -0,0 +1,64 @@
+create session table my_private_table(x integer primary key, y integer);
+insert into my_private_table values (generate_series(1,10000), generate_series(1,10000));
+select count(*) from my_private_table;
+ count 
+-------
+ 10000
+(1 row)
+
+\c
+select count(*) from my_private_table;
+ count 
+-------
+     0
+(1 row)
+
+select * from my_private_table where x=10001;
+ x | y 
+---+---
+(0 rows)
+
+insert into my_private_table values (generate_series(1,100000), generate_series(1,100000));
+create index on my_private_table(y);
+select * from my_private_table where x=10001;
+   x   |   y   
+-------+-------
+ 10001 | 10001
+(1 row)
+
+select * from my_private_table where y=10001;
+   x   |   y   
+-------+-------
+ 10001 | 10001
+(1 row)
+
+select count(*) from my_private_table;
+ count  
+--------
+ 100000
+(1 row)
+
+\c
+select * from my_private_table where x=100001;
+ x | y 
+---+---
+(0 rows)
+
+select * from my_private_table order by y desc limit 1;
+ x | y 
+---+---
+(0 rows)
+
+insert into my_private_table values (generate_series(1,100000), generate_series(1,100000));
+select * from my_private_table where x=100001;
+ x | y 
+---+---
+(0 rows)
+
+select * from my_private_table order by y desc limit 1;
+   x    |   y    
+--------+--------
+ 100000 | 100000
+(1 row)
+
+drop table  my_private_table;
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index fc0f141..507cf7d 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -107,7 +107,7 @@ test: json jsonb json_encoding jsonpath jsonpath_encoding jsonb_jsonpath
 # NB: temp.sql does a reconnect which transiently uses 2 connections,
 # so keep this parallel group to at most 19 tests
 # ----------
-test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion truncate alter_table sequence polymorphism rowtypes returning largeobject with xml
+test: plancache limit plpgsql copy2 temp global_temp session_table domain rangefuncs prepare conversion truncate alter_table sequence polymorphism rowtypes returning largeobject with xml
 
 # ----------
 # Another group of parallel tests
diff --git a/src/test/regress/serial_schedule b/src/test/regress/serial_schedule
index 68ac56a..3890777 100644
--- a/src/test/regress/serial_schedule
+++ b/src/test/regress/serial_schedule
@@ -172,6 +172,8 @@ test: limit
 test: plpgsql
 test: copy2
 test: temp
+test: global_temp
+test: session_table
 test: domain
 test: rangefuncs
 test: prepare
diff --git a/src/test/regress/sql/global_temp.sql b/src/test/regress/sql/global_temp.sql
new file mode 100644
index 0000000..3058b9b
--- /dev/null
+++ b/src/test/regress/sql/global_temp.sql
@@ -0,0 +1,151 @@
+--
+-- GLOBAL TEMP
+-- Test global temp relations
+--
+
+-- Test ON COMMIT DELETE ROWS
+
+CREATE GLOBAL TEMP TABLE global_temptest(col int) ON COMMIT DELETE ROWS;
+
+BEGIN;
+INSERT INTO global_temptest VALUES (1);
+INSERT INTO global_temptest VALUES (2);
+
+SELECT * FROM global_temptest;
+COMMIT;
+
+SELECT * FROM global_temptest;
+
+DROP TABLE global_temptest;
+
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temptest(col) ON COMMIT DELETE ROWS AS SELECT 1;
+
+SELECT * FROM global_temptest;
+COMMIT;
+
+SELECT * FROM global_temptest;
+
+DROP TABLE global_temptest;
+
+-- Test foreign keys
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temptest1(col int PRIMARY KEY);
+CREATE GLOBAL TEMP TABLE global_temptest2(col int REFERENCES global_temptest1)
+  ON COMMIT DELETE ROWS;
+INSERT INTO global_temptest1 VALUES (1);
+INSERT INTO global_temptest2 VALUES (1);
+COMMIT;
+SELECT * FROM global_temptest1;
+SELECT * FROM global_temptest2;
+
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temptest3(col int PRIMARY KEY) ON COMMIT DELETE ROWS;
+CREATE GLOBAL TEMP TABLE global_temptest4(col int REFERENCES global_temptest3);
+COMMIT;
+
+-- For partitioned temp tables, ON COMMIT actions ignore storage-less
+-- partitioned tables.
+BEGIN;
+CREATE GLOBAL TEMP TABLE temp_parted_oncommit (a int)
+  PARTITION BY LIST (a) ON COMMIT DELETE ROWS;
+CREATE GLOBAL TEMP TABLE temp_parted_oncommit_1
+  PARTITION OF temp_parted_oncommit
+  FOR VALUES IN (1) ON COMMIT DELETE ROWS;
+INSERT INTO temp_parted_oncommit VALUES (1);
+COMMIT;
+-- partitions are emptied by the previous commit
+SELECT * FROM temp_parted_oncommit;
+DROP TABLE temp_parted_oncommit;
+
+-- Using ON COMMIT DELETE on a partitioned table does not remove
+-- all rows if partitions preserve their data.
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temp_parted_oncommit_test (a int)
+  PARTITION BY LIST (a) ON COMMIT DELETE ROWS;
+CREATE GLOBAL TEMP TABLE global_temp_parted_oncommit_test1
+  PARTITION OF global_temp_parted_oncommit_test
+  FOR VALUES IN (1) ON COMMIT PRESERVE ROWS;
+INSERT INTO global_temp_parted_oncommit_test VALUES (1);
+COMMIT;
+-- Data from the remaining partition is still here as its rows are
+-- preserved.
+SELECT * FROM global_temp_parted_oncommit_test;
+-- two relations remain in this case.
+SELECT relname FROM pg_class WHERE relname LIKE 'global_temp_parted_oncommit_test%';
+DROP TABLE global_temp_parted_oncommit_test;
+
+-- Check dependencies between ON COMMIT actions with inheritance trees.
+-- Data on the parent is removed, and the child goes away.
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temp_inh_oncommit_test (a int) ON COMMIT DELETE ROWS;
+CREATE GLOBAL TEMP TABLE global_temp_inh_oncommit_test1 ()
+  INHERITS(global_temp_inh_oncommit_test) ON COMMIT PRESERVE ROWS;
+INSERT INTO global_temp_inh_oncommit_test1 VALUES (1);
+INSERT INTO global_temp_inh_oncommit_test VALUES (1);
+COMMIT;
+SELECT * FROM global_temp_inh_oncommit_test;
+-- two relations remain
+SELECT relname FROM pg_class WHERE relname LIKE 'global_temp_inh_oncommit_test%';
+DROP TABLE global_temp_inh_oncommit_test1;
+DROP TABLE global_temp_inh_oncommit_test;
+
+-- Global temp table cannot inherit from temporary relation
+BEGIN;
+CREATE TEMP TABLE global_temp_table (a int) ON COMMIT DELETE ROWS;
+CREATE GLOBAL TEMP TABLE global_temp_table1 ()
+  INHERITS(global_temp_table) ON COMMIT PRESERVE ROWS;
+ROLLBACK;
+
+-- Temp table can inherit from global temporary relation
+BEGIN;
+CREATE GLOBAL TEMP TABLE global_temp_table (a int) ON COMMIT DELETE ROWS;
+CREATE TEMP TABLE temp_table1 ()
+  INHERITS(global_temp_table) ON COMMIT PRESERVE ROWS;
+CREATE TEMP TABLE temp_table2 ()
+  INHERITS(global_temp_table) ON COMMIT DELETE ROWS;
+INSERT INTO temp_table2 VALUES (2);
+INSERT INTO temp_table1 VALUES (1);
+INSERT INTO global_temp_table VALUES (0);
+SELECT * FROM global_temp_table;
+COMMIT;
+SELECT * FROM global_temp_table;
+DROP TABLE temp_table2;
+DROP TABLE temp_table1;
+DROP TABLE global_temp_table;
+
+-- Global temp table can inherit from normal relation
+BEGIN;
+CREATE TABLE normal_table (a int);
+CREATE GLOBAL TEMP TABLE temp_table1 ()
+  INHERITS(normal_table) ON COMMIT PRESERVE ROWS;
+CREATE GLOBAL TEMP TABLE temp_table2 ()
+  INHERITS(normal_table) ON COMMIT DELETE ROWS;
+INSERT INTO temp_table2 VALUES (2);
+INSERT INTO temp_table1 VALUES (1);
+INSERT INTO normal_table VALUES (0);
+SELECT * FROM normal_table;
+COMMIT;
+SELECT * FROM normal_table;
+DROP TABLE temp_table2;
+DROP TABLE temp_table1;
+DROP TABLE normal_table;
+
+-- Check SERIAL and BIGSERIAL pseudo-types
+CREATE GLOBAL TEMP TABLE global_temp_table ( aid BIGSERIAL, bid SERIAL );
+CREATE SEQUENCE test_sequence;
+INSERT INTO global_temp_table DEFAULT VALUES;
+INSERT INTO global_temp_table DEFAULT VALUES;
+INSERT INTO global_temp_table DEFAULT VALUES;
+SELECT * FROM global_temp_table;
+SELECT NEXTVAL( 'test_sequence' );
+\c
+SELECT * FROM global_temp_table;
+SELECT NEXTVAL( 'test_sequence' );
+INSERT INTO global_temp_table DEFAULT VALUES;
+INSERT INTO global_temp_table DEFAULT VALUES;
+INSERT INTO global_temp_table DEFAULT VALUES;
+SELECT * FROM global_temp_table;
+SELECT NEXTVAL( 'test_sequence' );
+DROP TABLE global_temp_table;
+DROP SEQUENCE test_sequence;
diff --git a/src/test/regress/sql/session_table.sql b/src/test/regress/sql/session_table.sql
new file mode 100644
index 0000000..c6663dc
--- /dev/null
+++ b/src/test/regress/sql/session_table.sql
@@ -0,0 +1,18 @@
+create session table my_private_table(x integer primary key, y integer);
+insert into my_private_table values (generate_series(1,10000), generate_series(1,10000));
+select count(*) from my_private_table;
+\c
+select count(*) from my_private_table;
+select * from my_private_table where x=10001;
+insert into my_private_table values (generate_series(1,100000), generate_series(1,100000));
+create index on my_private_table(y);
+select * from my_private_table where x=10001;
+select * from my_private_table where y=10001;
+select count(*) from my_private_table;
+\c
+select * from my_private_table where x=100001;
+select * from my_private_table order by y desc limit 1;
+insert into my_private_table values (generate_series(1,100000), generate_series(1,100000));
+select * from my_private_table where x=100001;
+select * from my_private_table order by y desc limit 1;
+drop table  my_private_table;