Subject Re: [ib-support] Strange query problem
Author Helen Borrie
At 04:39 PM 12/02/2003 +0200, you wrote:

>Hi all,
>I have a query:
>"select hist.cguid from con_discon_info hist"

This query has no ordering, joins, groupings or where clause. Why do you
think an index could/should/would be used?

>Table "con_discon_info" has an index on field "cguid".
>After query execution I can see in the performance monitor that all of
>the reads where non-indexed reads
>If I modify the querylike this:
>"select hist.cguid from con_discon_info hist group by cguid"
> ^^^^^^^^^^^^^^^
>All reads become indexed ?????

The index is used because it will help the sorting for the grouping.