Re: BUG #16327: Too many files in pg_replslot folder

On Sun, 29 Mar 2020 at 11:49, PG Bug reporting form <noreply(at)postgresql(dot)org>
wrote:

>
> P.S. Replication on PostgreSql 11.1 (with default settings) worked fine
> with
> inserting 4.5 million rows. The xid - * - lsn - * - *. Snap files were
> smaller and larger in size. But if there were several inserts in a row of
> 4.5 million lines, an error appeared: ERROR: out of memory.
>
> Could you provide a test case? Are you using subtransactions?
logical_decoding_work_mem [1] was added in v13 to ameliorate some high
memory usage while decoding transactions. It is weird that it does not 'out
of memory' in v11 too (v11 introduced Generational memory allocator to
reduce logical decoding memory usage); I expect a high memory usage in v10
in a big transaction scenario.

If you are looking for a workaround, you should try to disable all
subscriptions and then enable only one at a time.

[1]
https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=cec2edfa7859279f36d2374770ca920c59c73dd8

Regards,

--
Euler Taveira http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services