--- 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.

PK