2009/8/12 Svein Erling Tysvær <svein.erling.tysvaer@...>:

> Why? You're only selecting the first 25 and using the UNQ_TBLOUTSTATION_2 index, Firebird doesn't have to check whether there are more than these 25 rows that meet the criteria.

I thought it would be selecting all rows that meet the criteria, then
sorting to determine the first 25

>
> HTH,
> Set
>
> -----Original Message-----
> From: firebird-support@yahoogroups.com [mailto:firebird-support@yahoogroups.com] On Behalf Of Nick Upson
> Sent: 12. august 2009 15:35
> To: firebird-support@yahoogroups.com
> Subject: Re: [firebird-support] query speed - confusing
>
> 2009/8/12 Anderson Farias <peixedragao@...>:
>> Hi,
>>
>>
>> About the 1st query:
>>
>>>PLAN JOIN (JOIN (JOIN (O NATURAL, OM INDEX (FK_TBLOSMETRI