Buffer pool disfavoring

Have you ever wondered why DBCC CHECKDB, for instance, doesn’t flush the buffer pool when it runs on a database that is larger than the memory capacity of the server? There’s cool mechanism that it uses called disfavoring. When a buffer is no longer required, the buffer can be marked as the least recently used of […]

Page Life Expectancy isn’t what you think…

There’s a lot of controversy about the Buffer Manager performance object counter Page Life Expectancy – mostly around people continuing to quote 300 as a threshold for starting to worry about there being a problem (which is just utter nonsense these days). That’s far too *low* to be the point at which to start worrying […]

Performance issues from wasted buffer pool memory

Back in April I kicked off a survey where I asked you all to send me some information about your buffer pools – how much memory is being used for data file pages and how much of that memory is storing empty space. I got back data from 1394 servers around the world – thanks! […]

Inside the Storage Engine: What’s in the buffer pool?

This is a quick post inspired by a question I was sent in email (thanks Marcos!) which very neatly lets me show a DMV I’ve been meaning to blog about for a while. And the weather here in Redmond really sucks right now so I can’t go outside – blogging will serve as my work-avoidance […]