Hi,

At June 19, 2003, 11:46, tomasz007 wrote:

> Also - let me understand what mechanism is used here:

> Does DB engine look at EACH of the condition parts (AND...OR...) and
> looks for ANY indexes (PK, FK, IX) containing ANY of the fields used
> in the given condition part?

In FB 1.0.x(and previous versions) and Interbase(all versions), all of
the WHERE clause conditions are evaluated. This behavior has been
changed in FB 1.5. The plan that is retrieved will be for almost all
the areas where indices can be used, following the optimizer's logic.
The plan is to help the engine to retrieve the data from the table.
Also, the optimizer has been improved in FB 1.5.

--
Best regards,
Daniel Rail
Senior System Engineer
ACCRA Group Inc. (www.accra.ca)
ACCRA Med Software Inc. (www.filopto.com)