Well, for SELECT request pgsql runs well, although it's a little slower than firebird & MySQL. The problem is especially for INSERT request. It's strange there's a lot of disk access, as if it doesn't use the cache or something like that (I'm not a db expert). The application runs on windows 2000 SP4 english, developped in Delphi 7 and access the database using ZeosLib 6.1.5 (I have also tried with 6.5.1-alpha 2). We don't make a lot of request in our application. We use MS-Access 97 and we want to change for an SQL compliant open source database. Out application with pgsql (but I think the problem is zeoslib) is a little slower than ms-access ! We have good results with MySQL and Firebird (using zeoslib). Thank you ---------------------------(end of broadcast)--------------------------- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match