Prevent long-term memory leakage in autovacuum launcher. get_database_list() failed to restore the caller's memory context, instead leaving current context set to TopMemoryContext which is how CommitTransactionCommand() leaves it. The callers both think they are using short-lived contexts, for the express purpose of not having to worry about cleaning up individual allocations. The net effect therefore is that supposedly short-lived allocations could accumulate indefinitely in the launcher's TopMemoryContext.
Although this has been broken for a long time, it seems we didn't have any obvious memory leak here until v15's rearrangement of the stats logic. I (tgl) am not entirely convinced that there's no other leak at all, though, and we're surely at risk of adding one in future back-patched fixes. So back-patch to all supported branches, even though this may be only a latent bug in pre-v15. Reid Thompson Discussion: https://postgr.es/m/[email protected] Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/1c1294be716d96e804aadafc249fcbfa8367621d Modified Files -------------- src/backend/postmaster/autovacuum.c | 3 +++ 1 file changed, 3 insertions(+)
