Re: Table refer leak in logical replication

On Mon, Apr 19, 2021 at 08:09:05PM +0900, Amit Langote wrote:
> On Mon, Apr 19, 2021 at 7:00 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
>> It seems like the memory will be freed after we apply the truncate
>> because we reset the ApplyMessageContext after applying each message,
>> so maybe we don't need to bother about it.
>
> Yes, ApplyMessageContext seems short-lived enough for this not to
> matter.  In the case of ExecuteTruncateGuts(), it's PortalContext, but
> we don't seem to bother about leaking into that one too.

Sorry for the dump question because I have not studied this part of
the code in any extensive way, but how many changes at maximum can be
applied within a single ApplyMessageContext?  I am wondering if we
could run into problems depending on the number of relations touched
within a single message, or if there are any patches that could run
into problems because of this limitation, meaning that we may want to
add a proper set of comments within this area to document the
limitations attached to a DML operation applied.
--
Michael