Horton

Re: Lots of memory allocated when reassigning Large Objects

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Guillaume Lelarge <guillaume@lelarge.info>
Cc: Justin Pryzby <pryzby@telsasoft.com>, PostgreSQL Developers <pgsql-hackers@postgresql.org>
Date: 2021-11-29T23:25:09Z
Lists: pgsql-hackers 
Guillaume Lelarge <guillaume@lelarge.info> writes:
> Le lun. 29 nov. 2021 à 22:27, Tom Lane <tgl@sss.pgh.pa.us> a écrit :
>> I'm checking it in HEAD though; perhaps there's something else wrong
>> in the back branches?

> That's also what I was thinking. I was only trying with v14. I just checked
> with v15devel, and your patch works alright. So there must be something
> else with back branches.

AFAICT the patch fixes what it intends to fix in v14 too.  The reason the
residual leak is worse in v14 is that the sinval message queue is bulkier.
We improved that in HEAD in commit 3aafc030a.  I'm not sure if I want to
take the risk of back-patching that, even now that it's aged a couple
months in the tree.  It is a pretty localized fix, but it makes some
assumptions about usage patterns that might not hold up.

			regards, tom lane

Commits

  1. Avoid leaking memory during large-scale REASSIGN OWNED BY operations.

  2. Reduce memory consumption for pending invalidation messages.