Subject Re: [ib-support] Adding index does nothing to select disctinct
Author Svein Erling Tysvaer
Hi Mark!

At 17:39 12.09.2002 +1000, you wrote:
>We have tables of factory work pieces that grow by hundreds or records
>daily. I
>want to be able to offer the users a selection of all jobs on rthe table. I
>tried doing
>SELECT DISTINCT(JOB_NUMBER) FROM SAWMEMEBRS
>with out an index on SAWMEMBERS(JOB_NUMBER)
>It was taking 6 secs +- a couple of seconds.
>
>Then I did
>CREATE INDEX SM_JOBNUMBER ON SAWMEMBERS(JOB_NUMBER)
>and there was no apparent speed benefit. I even quiet the test program,
>got back
>in,listed the indexes, swa that it was there, and still there was no
>increase in
>speed. That's longer than we'd like to make the users wait.
>
>Am i missing something?

Yes, most likely. At least I cannot see anything you write here that should
influence the speed very much. What is your WHERE clause like? If you add
several hundred each day and want to return every row added the last
century, then six seconds is not all too bad. However, in such a case you
might want to consider redesigning your mind from desktop to client/server
development ;o)

Basically, give us some more information. Indexes normally doesn't matter
much for the fields you select, but they can greatly improve the speed to
execute your WHERE criteria.

Set