Re: slow delete...

thanks a lot. I imagine this will help me a lot. I will give it a try!!!

One more question: in the explain output, what is that "Bitmap Heap Scan on test"?, is it a bad thing (a table scan)? I would love to see the index scan instead of this Heap scan... what does "Heap Scan" actually do here?

Bitmap Heap Scan on test (cost=2110.49..10491.57 rows=79766 width=6)
Recheck Cond: ((cola)::text = 'abc'::text)
-> Bitmap Index Scan on test_cola_idx (cost=0.00..2090.55 rows=79766 width=0)
Index Cond: ((cola)::text = 'abc'::text)
(4 rows)

Thanks again,
Jessica

----- Original Message ----
From: Charles Duffy <charles(dot)duffy(at)gmail(dot)com>
To: Jessica Richard <rjessil(at)yahoo(dot)com>
Cc: pgsql-admin(at)postgresql(dot)org
Sent: Friday, July 4, 2008 3:17:43 AM
Subject: Re: [ADMIN] slow delete...

> by the way, there is a foreign key on another table that references the
> primary key col0 on table test.
>

Try putting an index on the FK column in the other table. Analyse the
table. Test by starting a transaction then
issuing: explain analyze delete from test where cola = 'abc'. Should be faster.

Charles Duffy