Hi.
I used to think that $subject didn't happen, but it actually does and ends
up consuming a fixed 8192 bytes on the disk.
create table p (a int[]) partition by list (a);
CREATE TABLE
select pg_table_size('p');
pg_table_size
---------------
8192
(1 row)
select pg_relation_size(c1.oid) as p_size,
pg_relation_size(c1.reltoastrelid) as p_toast_heap_size,
pg_relation_size(c2.oid) as p_toast_index_size
from pg_class c1, pg_class c2, pg_index i
where c1.relname = 'p' and
c1.reltoastrelid = i.indrelid and
c2.oid = i.indexrelid;
p_size | p_toast_heap_size | p_toast_index_size
--------+-------------------+--------------------
0 | 0 | 8192
(1 row)
I think we should prevent this, a fix for which is implemented by the
attached patch.
Thanks,
Amit
From b84ee9f5aed9519d5976dc1a6c8f501d0122a686 Mon Sep 17 00:00:00 2001
From: amit <[email protected]>
Date: Tue, 16 Jan 2018 19:08:11 +0900
Subject: [PATCH v1] Do not create TOAST table for partitioned tables
---
src/backend/catalog/toasting.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/src/backend/catalog/toasting.c b/src/backend/catalog/toasting.c
index 0b4b5631a1..5e84f28201 100644
--- a/src/backend/catalog/toasting.c
+++ b/src/backend/catalog/toasting.c
@@ -393,6 +393,7 @@ create_toast_table(Relation rel, Oid toastOid, Oid
toastIndexOid,
* (1) there are any toastable attributes, and (2) the maximum length
* of a tuple could exceed TOAST_TUPLE_THRESHOLD. (We don't want to
* create a toast table for something like "f1 varchar(20)".)
+ * No need to create a TOAST table for partitioned tables.
*/
static bool
needs_toast_table(Relation rel)
@@ -404,6 +405,9 @@ needs_toast_table(Relation rel)
int32 tuple_length;
int i;
+ if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+ return false;
+
tupdesc = rel->rd_att;
for (i = 0; i < tupdesc->natts; i++)
--
2.11.0
