At 06:53 PM 23/04/2007, you wrote:

>--- In firebird-support@yahoogroups.com, Helen Borrie <helebor@...>
>wrote:
> > It depends, but not usually. It would use indexes if there were
> > useful ones available. However, an equality search on both fields of
> > a two-field index key is nothing like the search that you
> > described.
>
>I have just tried a single update UPDATE ... WHERE A=1 AND B=2 AND C=3
>after restarting my machine. I expected this to be instant as there is
>only one record. It turned out to be around 5 minutes. When I did it
>again the second time, it was instant.
>
> > However, your custom plan provided nothing useful for the search,
> > only a forced (unnecessarily doubled) use of the PK index for
>ordering.
> >
>
>Actually, what I was trying to say in my original post was that the
>performance is horrible with or without the custom plan. I don't
>really want to use the custom plan.

Did you index B and C individually, as suggested?

./heLen