time_lord,

are you sure they are exactly same release?(v1.5.1)
how can you be so sure about different optimisation,
did you compare plans for both, could you show us them?

Different HW and SW platforms may run in different speeds.
even two same machines will work in different speeds.
disc organisation and RAM organisation and usage can not be same.
Computer oscilators may be work at fixed frequence(except mobiles)
but computers don't work at fixed speed.
There are alot of components and HW IRQs arised asynchronously...

Only complaint can not help you or anybody,
you need to show us your table&index structers, your query and its
plan text created by FB.

Regards.

Ali


--- In firebird-support@yahoogroups.com, "phil_hhn" <time_lord@...>
wrote:

>
> Hi,
> We got to the bottom of a very slow query running on Mac OSX

(Firebird

> 1.5.1). We moved a couple of things around in the query (logically

the

> same query) and a 20second wait reduced to practically nothing.
> Unfortunately this has ruined the performance for the same query

when

> running on Windows.
>
> It seems therefore there are significant differences in query
> optimisation on the two platforms (we would have assumed the

optimiser

> would be the same on both!).
>
> In practice we have a Java application, connecting to a database

via

> JDBC; the database may be on either a Mac or Windows. For now it

seems

> we have to send different queries depending on the database

platform

> because of the way they perform.
> Is there a way to ask the JDBC driver what platform the database is
> on? Or give the optimiser some hints as to how it should run the
> query? The latter would be ok, except that we sometimes connect to

MS

> SQL Server databases, so we want 'plain-vanilla' queries where

possible...

>
> Thanks in advance
>