I use zip like you. Then I execute like SuperClassic. My application uses embeded, which is SuperClassic too. If I execute the query from my application (embeded FB) I get exactly same performance than when I do it from FlameRobin.

I enabled in firebird.conf the parameter DefaultDbCachePages = 2048, but after that the performace was 1 minute slower.

I don't think this problem is about parameters, there is something that changed a lot between 2.5.0 and 2.5.8 that is making this queries to go that slow.

What parameter (and how) do I have to change page buffer parameter?. Is it possible to set it in the connection parameters?.

Thank you!