Re: PATCH: logical_work_mem and logical streaming of large in-progress transactions

On Thu, Oct 3, 2019 at 1:18 PM Dilip Kumar <dilipbalaut(at)gmail(dot)com> wrote:
>

As mentioned by me a few days back that the first patch in this series
is ready to go [1] (I am hoping Tomas will pick it up), so I have
started the review of other patches

Review/Questions on 0002-Immediately-WAL-log-assignments.patch
-------------------------------------------------------------------------------------------------
1. This patch adds the top_xid in WAL whenever the first time WAL for
a subtransaction XID is written to correctly decode the changes of
in-progress transaction. This patch also removes logging and applying
WAL for XLOG_XACT_ASSIGNMENT which might have some effect. As replay
of that, it prunes KnownAssignedXids to prevent overflow of that
array. See comments in procarray.c (KnownAssignedTransactionIds
sub-module). Can you please explain how after removing the WAL for
XLOG_XACT_ASSIGNMENT, we will handle that or I am missing something
and there is no impact of same?

2.
+#define XLOG_INCLUDE_INVALS 0x08 /* include invalidations */

This doesn't seem to be used in this patch.

[1] - https://www.postgresql.org/message-id/CAA4eK1JM0%3DRwODZQrn8DTQ3dbcb9xwKDdHCmVOryAk_xoKf9Nw%40mail.gmail.com

--
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com