On 2017/03/23 23:47, Amit Langote wrote:
> On Thu, Mar 23, 2017 at 11:27 PM, Maksim Milyutin
> <m.milyu...@postgrespro.ru> wrote:
>> Hi!
>>
>> I have noticed that there is scheduled unlinking of nonexistent physical
>> storage under partitioned table when we execute DROP TABLE statement on this
>> partitioned table. Though this action doesn't generate any error under
>> typical behavior of postgres because the error of storage's lack is caught
>> through if-statement [1] I think it is not safe.
>>
>> My patch fixes this issue.
>>
>> 1. src/backend/storage/smgr/md.c:1385
>
> Good catch, will incorporate that in the main patch.
And here is the updated patch.
Thanks,
Amit
>From aed0685b6bfb99a301e674221fb393cc4e660461 Mon Sep 17 00:00:00 2001
From: amit <amitlangot...@gmail.com>
Date: Tue, 24 Jan 2017 14:22:34 +0900
Subject: [PATCH] Do not allocate storage for partitioned tables.
Currently, it is not possible to insert any data into a partitioned
table. So they're empty at all times, which means it is wasteful to
allocate relfilenode and related storage objects.
Also documented the fact that specifying storage options for partitioned
tables is ineffective at the moment.
---
doc/src/sgml/ref/create_table.sgml | 6 ++++++
src/backend/catalog/heap.c | 17 ++++++++++-------
2 files changed, 16 insertions(+), 7 deletions(-)
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 9ed25c05da..7ac55b17fa 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -1040,6 +1040,12 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI
will use the table's parameter value.
</para>
+ <para>
+ Note that specifying the following parameters for partitioned tables has
+ no effect at the moment. You must specify them for individual leaf
+ partitions if necessary.
+ </para>
+
<variablelist>
<varlistentry>
diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c
index 41c0056556..2f5090b183 100644
--- a/src/backend/catalog/heap.c
+++ b/src/backend/catalog/heap.c
@@ -291,6 +291,7 @@ heap_create(const char *relname,
case RELKIND_VIEW:
case RELKIND_COMPOSITE_TYPE:
case RELKIND_FOREIGN_TABLE:
+ case RELKIND_PARTITIONED_TABLE:
create_storage = false;
/*
@@ -1345,14 +1346,13 @@ heap_create_with_catalog(const char *relname,
if (oncommit != ONCOMMIT_NOOP)
register_on_commit_action(relid, oncommit);
- if (relpersistence == RELPERSISTENCE_UNLOGGED)
- {
- Assert(relkind == RELKIND_RELATION || relkind == RELKIND_MATVIEW ||
- relkind == RELKIND_TOASTVALUE ||
- relkind == RELKIND_PARTITIONED_TABLE);
-
+ /*
+ * We do not want to create any storage objects for a partitioned
+ * table, including the init fork.
+ */
+ if (relpersistence == RELPERSISTENCE_UNLOGGED &&
+ relkind != RELKIND_PARTITIONED_TABLE)
heap_create_init_fork(new_rel_desc);
- }
/*
* ok, the relation has been cataloged, so close our relations and return
@@ -1376,6 +1376,9 @@ heap_create_with_catalog(const char *relname,
void
heap_create_init_fork(Relation rel)
{
+ Assert(rel->rd_rel->relkind == RELKIND_RELATION ||
+ rel->rd_rel->relkind == RELKIND_MATVIEW ||
+ rel->rd_rel->relkind == RELKIND_TOASTVALUE);
RelationOpenSmgr(rel);
smgrcreate(rel->rd_smgr, INIT_FORKNUM, false);
log_smgrcreate(&rel->rd_smgr->smgr_rnode.node, INIT_FORKNUM);
--
2.11.0
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