On 2-11-2012 11:09, Jaume Llunell Gómez wrote:

> Hi,
>
> when i execute a long query with Firebird 2.5.2 with various LEFT JOIN to
> procedures and i get a plan like this:
>
> PLAN
> JOIN *(* .... *)*
> *(*CUSTOMERS INDEX (CUSTOMERS_PK)*)*
> *(*PROCEDURE_1 NATURAL*)*
> *(*PROCEDURE_2 NATURAL*)*
> ....
>
> I don't undestand what kind of operation is executed between all the result
> sets of this statements because after all the parenthesis is no comma and
> there isn't any operation that surround all of them. So i don't undestand
> how this plan is executed.

I don't understand your question. A plan isn't executed, it is a
description how the engine will execute your query.

Mark
--
Mark Rotteveel