Re: optimising UNION performance

On mán, 2006-08-28 at 10:23 +0200, Rafal Pietrak wrote:
> Hi all,
>
> Is there a way to speed up the query to my 'grand total' logfile,
> constructed as a UNION of smaller (specialised) logfiles?
>

I do not know if this is relevant to your case, but
possibly you can use a UNION ALL instead of a UNION.

In many cases the UNION ALL gives petter performance,
as the unique step can be skipped, as well as a sort
needed by the unique.

gnari