On Wed, Nov 25, 2009 at 4:13 PM, Luca Tettamanti wrote:
>
>
> DELETE FROM t1 WHERE EXISTS (SELECT 1 FROM t2 WHERE t1.annotation_id =
> t2.annotation_id)
>
> performs event better:
>
> Seq Scan on t1 (cost=0.00..170388415.89 rows=22937406 width=6) (actual
> time=272.625..561241.294 rows=26185953
On Wed, Nov 25, 2009 at 04:22:47PM +0100, marcin mank wrote:
> On Tue, Nov 24, 2009 at 2:37 PM, Luca Tettamanti wrote:
> > -> HashAggregate (cost=1031681.15..1033497.20 rows=181605
> > width=8) (a
> > ctual time=571807.575..610178.552 rows=26185953 loops=1)
>
>
> This is Your problem.
On Tue, Nov 24, 2009 at 2:37 PM, Luca Tettamanti wrote:
> -> HashAggregate (cost=1031681.15..1033497.20 rows=181605 width=8)
> (a
> ctual time=571807.575..610178.552 rows=26185953 loops=1)
This is Your problem. The system`s estimate for the number of distinct
annotation_ids in t2 is w
Even though the column in question is not unique on t2 could you not
index it? That should improve the performance of the inline query.
Are dates applicable in any way? In some cases adding a date field,
partitioning or indexing on that and adding where date>x days. That
can be an effectiv
On Tuesday 24 November 2009, Thom Brown wrote:
>
> It's a shame there isn't a LIMIT option on DELETE so this can be done in
> small batches.
delete from table where pk in (select pk from table where delete_condition
limit X);
--
"No animals were harmed in the recording of this episode. We tri
On Tue, Nov 24, 2009 at 3:19 PM, Thom Brown wrote:
> 2009/11/24 Luca Tettamanti
>
> On Tue, Nov 24, 2009 at 3:59 PM, Jerry Champlin
>> wrote:
>> > You may want to consider using partitioning. That way you can drop the
>> > appropriate partition and never have the overhead of a delete.
>>
>> Hu
You may want to consider using partitioning. That way you can drop the
appropriate partition and never have the overhead of a delete.
Jerry Champlin|Absolute Performance Inc.|Mobile: 303-588-2547
-Original Message-
From: pgsql-performance-ow...@postgresql.org
[mailto:pgsql-performance-o
2009/11/24 Luca Tettamanti
> On Tue, Nov 24, 2009 at 3:59 PM, Jerry Champlin
> wrote:
> > You may want to consider using partitioning. That way you can drop the
> > appropriate partition and never have the overhead of a delete.
>
> Hum, I don't think it's doable in my case; the partitioning is
On Tue, Nov 24, 2009 at 3:59 PM, Jerry Champlin
wrote:
> You may want to consider using partitioning. That way you can drop the
> appropriate partition and never have the overhead of a delete.
Hum, I don't think it's doable in my case; the partitioning is not
know a priori. First t1 is fully pop
