Hi Helen

Thanks for an insightful reply, as always. Please read inline

--- In firebird-support@yahoogroups.com, Helen Borrie <helebor@...> wrote:
> Wrong. A WHERE clause is applied during the search for eligible records. The server has no idea about a "client side filter".

Okay, thanks for the clarification.

> Yes. NOT queries are inefficient. Period.

Okay.

> There are other things about your query that are inefficient. You are joining on non-indexed columns (which makes a difference in cases where an index could be used if one were available);

Actually tBOMIssue.iID is a PK and tWastedChit.itBMRID is it's FK counterpart and I have confirmed there is index present for both the fields in question

>and converting regular column outputs to expression fields unnecessarily is another slowdown.

Okay, this I can see, thanks for the correction.

Thanks and regards.
Bhavbhuti