On 5.11.2015 13:25, Dmitry Yemanov [email protected] [firebird-support] wrote: > > 05.11.2015 14:12, Josef Kokeš [email protected] 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. >
Hi Dmitry, the execution plans were exactly the same (diff) for all tested versions: a long chain of PLAN JOIN (JOIN (... INDEX (name1)) INDEX (name2)). I will see about 2.5.5 how it performs. Josef
