This is a known issues with pre 8.0 postgresql...
Dave
On Thu, 2004-08-19 at 17:01, Jeff Amiel wrote:
> 7.4.2 running on FreeBSD 5.4.2
>
> I have a table (called "draft" ) that has a bigserial as the primary key.
>
> "check_id bigserial NOT NULL"
>
> I do NOT have an additional index on that column.
>
> I have a plpgsql function (stored procedure) that selects from that
> table based on the primary key field
>
> "select into draftrow * from draft where check_id=draftid;"
> where draft id is declared in the DECLARE section as "draftid int8;"
>
> This query is woefully slow. Sequential scan on table
>
> However, if I modify the query as follows:
>
> "select into draftrow * from draft where check_id=int8(draftid);"
>
> Ultra mega speed improvement. Index scan using the primary key.
>
> I declared the compared value (draftid) as an int8, why should I have to
> cast it as such in the query to cause the optimizer to use the primary key?
>
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--
Dave Cramer
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www.postgresintl.com