Re: pgsql: Prevent instability in contrib/pageinspect's regression test.
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
Cc: Robert Haas <robertmhaas@gmail.com>, pgsql-hackers@lists.postgresql.org
Date: 2022-11-21T20:33:51Z
Lists: pgsql-hackers
Andres Freund <andres@anarazel.de> writes: > On 2022-11-21 15:12:15 -0500, Tom Lane wrote: >> If I were trying to find a better fix I'd be looking for ways for >> parallel workers to be able to read the parent's temp tables. >> (Perhaps that could tie in with the blue-sky discussion we had >> the other day about allowing autovacuum on temp tables??) > That'd be a nontrivial change, because we explicitly don't use any > locking for anything relating to localbuf.c. One possible benefit could > be that we could substantially reduce the code duplication between > "normal" bufmgr.c and localbuf.c. I didn't say this was easy ;-). Aside from locking, the local buffers are inside the process's address space and not accessible from outside. Maybe they could be mapped into a shared memory region instead? And there are optimizations like commit a7212be8b that depend on the assumption that nothing else is accessing our process's temp tables. That'd need a lot of thought, if we don't want to give up all the performance benefits of temp tables. regards, tom lane
Commits
-
Mark pageinspect's disk-accessing functions as parallel restricted.
- b8988cf1d0a7 15.2 landed
- aeaaf520f409 16.0 landed
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Prevent instability in contrib/pageinspect's regression test.
- e2933a6e1179 16.0 cited
-
Set cutoff xmin more aggressively when vacuuming a temporary table.
- a7212be8b9e0 14.0 cited