It’s just bad code or bad design … most of the time

Some years ago I wrote an article for the UKOUG magazine called “Want a faster database – Take a drive on the M25”.  For those not familiar with the United Kingdom, the M25 is one of its busiest roads (M = “motorway”) and because it moves so much traffic, and runs so close to capacity, it has often been referred to as “the world’s largest car park”.  Many people have probably spent a good part of their lives on the M25 Smile  I used the M25 as a metaphor for how database professionals can focus on the wrong things when trying to solve a performance problem, such as:

“I’m stuck in traffic…perhaps a faster car will help”

ie, throwing CPU at a problem that is not CPU bound will not help things, or

“I’m stuck in traffic…it must be the width of the paint on the lane markings”