So it seems like we have a candidate explanation. I'm a bit surprised
that StandbyReleaseLocks would get this slow if there are only a dozen
AccessExclusiveLocks in place at any one time, though. Perhaps that
was a low point and there are often many more?
Entirely possible that it was a low point. We'll set up some monitoring to track the number of AccessExclusiveLocks and see how much variance there is throughout the day.
Since we turned on the monitoring for that, we had a peak of 13,550 AccessExclusiveLocks. So far most of the samples have been in the double digit, with that and two other outliers: 6,118 and 12,747.
