Subject Re: [firebird-support] Re: Query performance with PLAN
Author Anderson Farias
Just to comment on...

I find FB optimizer just great! it finds the best path almost for all
queries... and when it does not it´s problably becouse you'd not give it the
chance to... some changes in the query or indices will help.

As Dmitry said, it can´t be perfect since it does not know every
query/tables/records/indices/crazyness someone will have... but thats not a
big deal...

...the only think any FB user needs is to understant *a very little* about
indices and selectivity and his done. I, for instace, never even needed to
define a plan myself (and thats a great tool) -- just changing the SQL,
define some new index and/or using 'triks' like the +0 is/was enougth for
me, and don't think my querys are small/simple, sometimes they're not.

And just to remember, there's a freeware tool out there called
'IBPlanalyzer' that's JUST GREAT helping on this job -- unfortunatly is made
for Interbase, but I use it for FB 1.5 with no problem (did not test against
2.0/2.1 yet). Hope someday FB gains a supertool like that too.


----- Original Message -----
From: "Dmitry Yemanov" <dimitr@...>

> Believe or not, but it's practically impossible to create an ideal
> optimizer. If you have test cases that prove the current optimization
> decisions wrong, feel free to enter a ticket to the tracker.
> Dmitry