Re: Recovery performance of DROP DATABASE with many tablespaces
Michael Paquier <michael@paquier.xyz>
From: Michael Paquier <michael@paquier.xyz>
To: Fujii Masao <masao.fujii@gmail.com>
Cc: "Jamison, Kirk" <k.jamison@jp.fujitsu.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2018-09-30T12:51:30Z
Lists: pgsql-hackers
On Tue, Jul 10, 2018 at 03:04:05PM +0900, Michael Paquier wrote: > It would be simple to measure the time it takes to replay this single > DROP DATABASE record by putting two gettimeofday() calls or such things > and then take the time difference. There are many methods that you > could use here, and I suppose that with a shared buffer setting of a > couple of GBs of shared buffers you would see a measurable difference > with a dozen of tablespaces or so. You could also take a base backup > after creating all the tablespaces, connect the standby and then drop > the database on the primary to see the actual time it takes. Your patch > looks logically correct to me because DropDatabaseBuffers is a > *bottleneck* with large shared_buffers, and it would be nice to see > numbers. This was a couple of months ago, and nothing has happened since with the patch waiting on author, so the patch is marked as returned with feedback. -- Michael
Commits
-
Make DROP DATABASE command generate less WAL records.
- e6d8069522c8 13.0 landed