Re: PostgreSQL and a Catch-22 Issue related to dead rows
Greg Sabino Mullane <htamfids@gmail.com>
From: Greg Sabino Mullane <htamfids@gmail.com>
To: Lars Aksel Opsahl <Lars.Opsahl@nibio.no>
Cc: "pgsql-performance@lists.postgresql.org"
<pgsql-performance@lists.postgresql.org>
Date: 2024-12-09T13:35:20Z
Lists: pgsql-performance
On Mon, Dec 9, 2024 at 6:03 AM Lars Aksel Opsahl <Lars.Opsahl@nibio.no> wrote: > In one case, we processed a total of 750 cells, with an overall runtime of > 40 hours. However, one specific cell took over 12 hours to complete, most > of which was spent on removing small areas by deleting edges in PostGIS > Topology. The root cause of this delay is related to removal of dead rows. > Can you please expand exactly what you mean by "removal of dead rows" here, and what the exact issue you are facing is? > By introducing periodic COMMIT statements and VACUUM (FULL) operations > Vacfull is a pretty rough solution, and almost always not the correct tool for the job, IMHO. Yes there are very good reason for the way removal for dead rows work now, > but is there any chance of adding an option when creating table to disable > this behavior for instance for unlogged tables ? > It's still not clear exactly what the ask is here, but there is little chance we would design an alternative MVCC system just to accommodate this use case. Cheers, Greg