Yes, the query operates only on indexed columns (all numeric(10)'s).
Column | Type |
Modifiers
-------------------------------+-----------------------------+--------------
---------------
user_account_id | numeric(10,0) | not null
[snip]
Indexes: user_account_pkey primary key btree (user_account_id),
Foreign Key constraints: $1 FOREIGN KEY (lang_id) REFERENCES lang(lang_id)
ON UPDATE NO ACTION ON DELETE NO ACTION,
$2 FOREIGN KEY (source_id) REFERENCES
source(source_id) ON UPDATE NO ACTION ON DELETE NO ACTION,
$3 FOREIGN KEY (user_role_id) REFERENCES
user_role(user_role_id) ON UPDATE NO ACTION ON DELETE NO ACTION
David
----- Original Message -----
From: "Joe Conway" <mail@joeconway.com>
To: "David Griffiths" <dgriffiths@boats.com>
Cc: <pgsql-performance@postgresql.org>
Sent: Sunday, October 12, 2003 6:37 PM
Subject: Re: [PERFORM] Another weird one with an UPDATE
> David Griffiths wrote:
> >>I think you want something like:
> >>UPDATE user_account SET last_name = 'abc'
> >> WHERE EXISTS (SELECT 1 FROM commercial_entity ce, commercial_service cs
> >> WHERE user_account.user_account_id = ce.user_account_id AND
> >> ce.commercial_entity_id = cs.commercial_entity_id);
> >
> > Unfort, this is still taking a long time.
> > -------
> > Seq Scan on user_account (cost=0.00..748990.51 rows=36242 width=716)
>
> Do you have an index on user_account.user_account_id?
>
> Joe
