Prevent loss of init fork when truncating an unlogged table.

Fixes bug #6635, reported by Akira Kurosawa.

diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c
index d029a25c11a375e71afa4a6bfbc0fe04445c0b43..2734ec865823a1501b7fc0dfcc0699f8c38f98ee 100644 (file)
--- 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 c94d9457223431c7419034fa53a63df03f668d2c..e23a3dab3cd0eceb9fe7e62373b71c0cfe607495 100644 (file)
--- 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 c0deab73ae616a9ba82add7590f3776fc0bbedfc..bc98d5d6fc1e789619ee04a4237f3e272a431eca 100644 (file)
--- 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);