Subject Big database optimization
I am runing WI-V2.5.2.26539 Firebird 2.5, on win 7 64 bit. Databse is more than 20 GB big, and I have tables which are really huge - millions of rows.

My query combines 6-7 tables, and all tables are searched with use of indexes, so altough tables are huge, query fethes only 10.000 rows, for example. So far so good. The issue I have is that if I run query firs time, it is very slow, even when using queries. Than , second time, cash is doing its, and query becomes fast. But than, when I change parameters for the query, again it is slow.

I tried with really bigger database cache - no improvement, only slower result.

Any advices, or links to some info articles ?