Re: planning issue - Mailing list pgsql-general

From Jeff Davis
Subject Re: planning issue
Date
Msg-id 1174074508.23455.344.camel@dogma.v10.wvs
Whole thread Raw
In response to Re: planning issue  ("Joshua D. Drake" <jd@commandprompt.com>)
Responses Re: planning issue  (Jonathan Vanasco <postgres@2xlp.com>)
Re: planning issue  ("John D. Burger" <john@mitre.org>)
List pgsql-general
On Fri, 2007-03-16 at 12:17 -0700, Joshua D. Drake wrote:
> >
> >         QUERY PLAN
> >
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
> >
> > Seq Scan on table_a  (cost=0.00..22779.68 rows=1 width=346)
> >    Filter: ((id <> 10001) AND (((field_1)::text ~~* '123'::text) OR
> > ((field_2)::text ~~* 'abc'::text)))
> >
> >
> > however, i have the following indexes:
> >
> >     "table_a__pkey" PRIMARY KEY, btree (id)
> >     "table_a__idx__field_1" btree (field_1)
> >     "table_a__idx__field_2" btree (field_2)
> >
> > can anyone offer advice to help me use the indexes on this ?
>
> create a function lower index and instead of calling ilike call ~
> lower('123')
>

To clarify a little:

CREATE INDEX table_a_lower_field_1_idx on table_a ((lower(field_1)));
CREATE INDEX table_a_lower_field_2_idx on table_a ((lower(field_2)));
SELECT
        *
FROM
        table_a
WHERE
        id != 10001
        AND
        (
                        ( lower(field_1) = '123' )
                        OR
                        ( lower(field_2) = 'abc' )
        )

That should be able to use your indexes correctly.

Regards,
    Jeff Davis


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