A few time ago I had the opportunity to investigate about an unexpected SPID (Session Process ID) change. The inquiry began when a customer of ours starts to complain for locks, and lock time out error. These locks sometime were more frequent and sometimes not. To investigate about this issue, I have taken two SQL Profiler trace files ...

From Red-Gate website you can download (for free) the ebook Performance Tuning with SQL Server Dynamic Management Views written by Louis Davidson (@drsql) and Tim Ford (@sqlagentman). DMVs are objects that publish information about the health state of a SQL Server instance. They allow you to monitor the heart of the system to diagnose ...

Every year at PASS, I do the same thing. I hmm and haw over which sessions I want to go to, and I end up making some tough choices at game time.  This year I believe I'll be pretty busy, so my typical pie-in-the-sky view of how much I'll be able to attend just isn't going to pan out.  Instead, I have selected 5 sessions that I really ...

The behavior of column matching in subqueries is a little peculiar, to say the least.  If you've been bitten by this behavior once, you're unlikely to have been bitten a second time, but for some of us it just takes a while to sink in. This morning I wasted a good five minutes ''troubleshooting'' a query that wasn't working out the way I ...