Sometimes my mainframe roots betray me. Let me take you back to those days when men were men and so on.
Back then a read was a read. It went from request to i/o handler to disk controller. No stopping for idle chat with the locking subsystem. Every millisecond counted.
But with Microsoft SQL Server a read (aka “SELECT” command) is not a just a read anymore, which caused a bit of consternation yesterday in our lead generation system some time after I had made what seemed an innocuous update.
The error reports started trickling in (see error image above) after I had gotten out to the golf course. Fortunately TempWorks superdevs Eric Anderson and Andy Cohen were around to cover my back and figure out that a SELECT command can also do a lock which in this case was causing a deadly embrace.
If you code SQL you might enjoy reading more here.