Erik Jones <erik@xxxxxxxxxx> writes: > We've recently made a couple changes to our system that have resulted > in a drastic increase in performance as well as some very confusing > changes to the database statistics, specifically > pg_stat_database.xact_commit. Here's the details: I'm kinda boggled too. I can see how increasing shared buffers could result in a drastic reduction in write rate, if the working set of your queries fits in the new space but didn't fit in the old. I have no idea how that leads to a drop in number of transactions committed though. It doesn't make sense that autovac would run less frequently, because it's driven by number of tuples changed not number of disk writes; and that could hardly account for a 10x drop anyway. Did you by any chance take note of exactly which processes were generating all the I/O or the CPU load? regards, tom lane
