Horton

Re: memory leak in trigger handling (since PG12)

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

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Tomas Vondra <tomas.vondra@enterprisedb.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2023-05-24T15:37:10Z
Lists: pgsql-hackers 
Tomas Vondra <tomas.vondra@enterprisedb.com> writes:
> While looking for other places allocating stuff in ExecutorState (for
> the UPDATE case) and leaving it there, I found two more cases:

> 1) copy_plpgsql_datums

> 2) make_expanded_record_from_tupdesc
>    make_expanded_record_from_exprecord

> All of this is calls from plpgsql_exec_trigger.

Can you show a test case in which this happens?  I added some
instrumentation and verified at least within our regression tests,
copy_plpgsql_datums' CurrentMemoryContext is always plpgsql's
"SPI Proc" context, so I do not see how there can be a query-lifespan
leak there, nor how your 0003 would fix it if there is.

			regards, tom lane

Commits

  1. Fix oversight in handling of modifiedCols since f24523672d

  2. Use per-tuple context in ExecGetAllUpdatedCols

  3. Generated columns