Re: Query plan w/ like clause question

On Wed, May 29, 2002 at 03:58:53PM -0500, Steve Wranovsky wrote:
>
> I am having some strange results using a "like" clause under 7.2.1 w/ Linux.

...

> When I try to a like clause with a '%' wildcard that will return the
> same results as the exact match, the query does a sequential scan
> instead of using the index, and takes a significant amount of time
> to execute.

An index scan can't be used for a LIKE unless you're running in the C
locale, because other locales may have sorting rules which would give
incorrect results. Probably you're using en_US? Unfortunately you
need to re-run "initdb" to change this, which means dumping and
restoring your databases. See section 3.2 of the Administrator's
Guide.

Richard