From 1331cc6c1ad2beba7985523508d6722dc865c337 Mon Sep 17 00:00:00 2001
From: Robert Haas <rhaas@postgresql.org>
Date: Fri, 11 May 2012 09:46:42 -0400
Subject: [PATCH] Prevent loss of init fork when truncating an unlogged table.
Fixes bug #6635, reported by Akira Kurosawa.
---
src/backend/catalog/heap.c | 32 +++++++++++++++++---------------
src/backend/commands/tablecmds.c | 4 ++++
src/include/catalog/heap.h | 2 ++
3 files changed, 23 insertions(+), 15 deletions(-)
diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c
index d029a25c11a..2734ec86582 100644
--- a/src/backend/catalog/heap.c
+++ b/src/backend/catalog/heap.c
@@ -1306,24 +1306,10 @@ heap_create_with_catalog(const char *relname,
if (oncommit != ONCOMMIT_NOOP)
register_on_commit_action(relid, oncommit);
- /*
- * If this is an unlogged relation, it needs an init fork so that it can
- * be correctly reinitialized on restart. Since we're going to do an
- * immediate sync, we only need to xlog this if archiving or streaming is
- * enabled. And the immediate sync is required, because otherwise there's
- * no guarantee that this will hit the disk before the next checkpoint
- * moves the redo pointer.
- */
if (relpersistence == RELPERSISTENCE_UNLOGGED)
{
Assert(relkind == RELKIND_RELATION || relkind == RELKIND_TOASTVALUE);
-
- RelationOpenSmgr(new_rel_desc);
- smgrcreate(new_rel_desc->rd_smgr, INIT_FORKNUM, false);
- if (XLogIsNeeded())
- log_smgrcreate(&new_rel_desc->rd_smgr->smgr_rnode.node,
- INIT_FORKNUM);
- smgrimmedsync(new_rel_desc->rd_smgr, INIT_FORKNUM);
+ heap_create_init_fork(new_rel_desc);
}
/*
@@ -1336,6 +1322,22 @@ heap_create_with_catalog(const char *relname,
return relid;
}
+/*
+ * Set up an init fork for an unlogged table so that it can be correctly
+ * reinitialized on restart. Since we're going to do an immediate sync, we
+ * only need to xlog this if archiving or streaming is enabled. And the
+ * immediate sync is required, because otherwise there's no guarantee that
+ * this will hit the disk before the next checkpoint moves the redo pointer.
+ */
+void
+heap_create_init_fork(Relation rel)
+{
+ RelationOpenSmgr(rel);
+ smgrcreate(rel->rd_smgr, INIT_FORKNUM, false);
+ if (XLogIsNeeded())
+ log_smgrcreate(&rel->rd_smgr->smgr_rnode.node, INIT_FORKNUM);
+ smgrimmedsync(rel->rd_smgr, INIT_FORKNUM);
+}
/*
* RelationRemoveInheritance
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index c94d9457223..e23a3dab3cd 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -1155,6 +1155,8 @@ ExecuteTruncate(TruncateStmt *stmt)
* deletion at commit.
*/
RelationSetNewRelfilenode(rel, RecentXmin);
+ if (rel->rd_rel->relpersistence == RELPERSISTENCE_UNLOGGED)
+ heap_create_init_fork(rel);
heap_relid = RelationGetRelid(rel);
toast_relid = rel->rd_rel->reltoastrelid;
@@ -1166,6 +1168,8 @@ ExecuteTruncate(TruncateStmt *stmt)
{
rel = relation_open(toast_relid, AccessExclusiveLock);
RelationSetNewRelfilenode(rel, RecentXmin);
+ if (rel->rd_rel->relpersistence == RELPERSISTENCE_UNLOGGED)
+ heap_create_init_fork(rel);
heap_close(rel, NoLock);
}
diff --git a/src/include/catalog/heap.h b/src/include/catalog/heap.h
index c0deab73ae6..bc98d5d6fc1 100644
--- a/src/include/catalog/heap.h
+++ b/src/include/catalog/heap.h
@@ -69,6 +69,8 @@ extern Oid heap_create_with_catalog(const char *relname,
bool use_user_acl,
bool allow_system_table_mods);
+extern void heap_create_init_fork(Relation rel);
+
extern void heap_drop_with_catalog(Oid relid);
extern void heap_truncate(List *relids);
--
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