Maybe unlikely, but not impossible - just because the database is 300GB doesn't mean that users weren't only querying a small portion of it (e.g. just the most current data) at the time when you were running the sar command. I also work with several DBs in that same size range, but most of it is historical and probably less than 5% of the blocks are used on a regular basis - that's how we get by with just a 3GB buffer cache on a 300GB database. I'm not trying to say that all your blocks are cached, just saying that I wouldn't ignore it as a real possibility so I'd recommend digging deeper to see if it's actually the case or not. Regards, Brandon ________________________________ Privileged/Confidential Information may be contained in this message or attachments hereto. Please advise immediately if you or your employer do not consent to Internet email for messages of this kind. Opinions, conclusions and other information in this message that do not relate to the official business of this company shall be understood as neither given nor endorsed by it.