Subject Re: FB 2.5.4 - new handling of IN SUBSELECT?
Author Dmitry Yemanov
05.11.2015 14:12, Josef KokeŇ° j.kokes@... wrote:
>
> I wonder: Was there any change in FB 2.5.4 which would slow down
> processing of WHERE field IN (subselect) a lot, compared to FB 2.5.3? I
> have been performing tests because a user of mine complained about slow
> speed of my database, and found out that my query in the form of:
>
> SELECT COUNT(*)
> FROM a_complex_view
> WHERE field1=1 AND field2<>2
> AND key_field IN (SELECT key_field FROM key_field_list)
>
> went from 2 seconds in FB 2.5.0-2.5.3 to 4 minutes in FB 2.5.4.

What is execution plan for v2.5.3 and v2.5.4? Also worth trying a v2.5.5
snapshot.


Dmitry