Re: Query Performance.

On Tue, 23 Jan 2001 14:10:05 GMT, Brian Peasland <peasland_at_edcmail.cr.usgs.gov> wrote:

>> I am curious to know why adding extra things to the query (I.E. The
>> view) shaved off 3 to 4 seconds.
>
>You'll answer your own question, and learn a lot about query
>optimization if you check out the EXPLAIN PLAN of the original query and
>the modified query. There could be a couple of reasons why the query
>executed faster.
> 1) Adding the "extra things" caused the optimizer to use an index.
>This sped up the query.
> 2) Adding the "extra things" caused the optimizer to *NOT* use an
>index. This sped up the query.
>
>These aren't the only reasons. Without seeing the EXPLAIN PLANs, it's
>hard for anyone to say as everything else is pure speculation.
How do I get an explain plan? Or at least, where is is explained in the docs?

Brian Received on Tue Jan 23 2001 - 08:45:12 CST