So, you asked this question both in ib-support and Firebird-Architect and
then replied to ib-support to an answer given in Firebird-Architect?
Confusing...

A plan just shows how IB/Fb will execute your statement. This plan is
generated when you prepare. There are plenty of ways to discover the plan,
the way I normally use is through the DSQL or Cursor tab of IB_SQL
(www.ibobjects.com). For your select it would probably be something like
PLAN JOIN(LIG_TDV Natural, ENT_TDV INDEX (OneOrMoreIndexes)). Probably the
worst plan you could get is a Natural on both tables, but if you've defined
indexes sensibly, then that would be no problem. Too many indexes can be
equally bad - never index a field with only a few possible values.

HTH,
Set
-I'm going to Fulda in a week!

At 13:29 09.05.2003 +0200, you wrote:

>Thanks for you help.
>
>What do you mean by PLAN's, the structure of the 2 tables ? (sorry i'm
>french :-))
>
> > Could you please show us your PLAN's and could you also run these tests on
> > Firebird 1.5. FB1.5 has an improved optimizer.
>
>ok, i'm going to download this new version and run the test again.
>
>Regards
>--------------------------------
>Cédric Joubert