Re: [PERFORM] LEFT JOIN optimization

2005-09-12 Thread Manfred Koizar
On Mon, 12 Sep 2005 00:47:57 +0300, Ksenia Marasanova <[EMAIL PROTECTED]> wrote: > -> Seq Scan on user_ (cost=0.00..7430.63 rows=12763 width=245) >(actual time=360.431..1120.012 rows=12763 loops=1) If 12000 rows of the given size are stored in more than 7000 pages, then there is a lot of free

Re: [PERFORM] LEFT JOIN optimization

2005-09-11 Thread Stephen Frost
* Ksenia Marasanova ([EMAIL PROTECTED]) wrote: > test=# explain analyze select * from user_ left join church on > user_.church_id = church.id; [...] > Total runtime: 2025.946 ms > (6 rows) > > test=# set enable_seqscan='false'; > SET > test=# explain analyze select * from user_ left join church o

Re: [PERFORM] LEFT JOIN optimization

2005-09-11 Thread Ksenia Marasanova
2005/9/12, Stephen Frost <[EMAIL PROTECTED]>: > * Ksenia Marasanova ([EMAIL PROTECTED]) wrote: > > Any tips are greatly appreciated. > > EXPLAIN ANALYZE of the same queries would be much more useful. Thanks, here it is: test=# explain analyze select * from user_ left join church on user_.church_

Re: [PERFORM] LEFT JOIN optimization

2005-09-11 Thread Stephen Frost
* Ksenia Marasanova ([EMAIL PROTECTED]) wrote: > Any tips are greatly appreciated. EXPLAIN ANALYZE of the same queries would be much more useful. Thanks, Stephen signature.asc Description: Digital signature

[PERFORM] LEFT JOIN optimization

2005-09-11 Thread Ksenia Marasanova
Hi list, I don't have much experience with Postgres optimization, somehow I was happily avoiding anything more difficult than simple select statement, and it was working all right. Now LEFT JOIN must be used, and I am not happy with the performance: It takes about 5 seconds to run very simple LEF