Thanks, Tom. I am wondering if there is way to obtain same performance as before. Like restoring performance statistics?! Simple analyze is not helping. And Vacuum is a overkill where there are no dead tuples. I am not setting any hint bits... I can verify this in new and old if you can provide a query or some method to verify this... I still have original copy of same database on a different server for comparison. -----Original Message----- From: Tom Lane <tgl@xxxxxxxxxxxxx> Sent: Sunday, December 24, 2023 10:12 AM To: Murthy Nunna <mnunna@xxxxxxxx> Cc: pgsql-admin@xxxxxxxxxxxxxx Subject: Re: Query Performance after pg_restore Murthy Nunna <mnunna@xxxxxxxx> writes: > I did pg_dump of a ~20TB database followed by pg_restore. I find simple queries like select count(*) running slow. I did a select count(*) on all tables before pg_dump which took ~4 hours. After pg_restore, same thing took 32 hours. My bet is that that was setting commit hint bits, and hence incurring a lot of writes. If the data is reasonably stable that's a one-time expense. regards, tom lane
