Subject Re: need help on optimization
Author russt4
--- In, "Ann W. Harrison"
<aharrison@i...> wrote:
> russt4 wrote:
> >
> >
> > Hello, I'm experiencing very slow performance on quite simple
> > queries. ... It appears that firebird is
> > searching over every row in the table, and isn't just using
> > the information in the index to construct the result.
> >
> Yes, that's part of the price of multi-version concurrency
control. The
> fact that a value is in the index does not mean that it's valid for
> transaction. It may have been deleted, updated, or inserted by a
> concurrent transaction. The only way to validate the data is to
> the actual records.

Ah, thanks for the explanation, Ann.