What your Postgres is waiting for, and why the dashboard can't tell you
· 14 min read
A checkout request was slow. The dashboard said the time went to the commit path and to disk reads. The team tried the two fixes that follow from that, and the slowest requests stayed about as slow. The cause was a lock that the dashboard ranked fifth, at 2% of the time. This post explains why a wait dashboard can be right about the time and wrong about the problem, using only what Postgres exposes today. It ends where the next post, about a tool that finds such causes, begins.