Eugene, As you've probably understood from your replies, DB_BLOCK_SIZE is the one parameter that can't be changed after the database is created (there are more options with 10g). Perhaps if you stated why you want to change this, we can provide you more useful suggestions. Often people assume stuff like by doubling the block size their performance will double. Also, this is a pretty old database version, and not the latest Windows server version. I'm always reluctant to make substantial changes on something that old. Might be a better idea to migrate the database to recent versions. Dennis Williams