Re: row filtering for logical replication

Greg Nancarrow <gregn4422@gmail.com>

From: Greg Nancarrow <gregn4422@gmail.com>

To: Euler Taveira <euler@eulerto.com>

Cc: Amit Kapila <amit.kapila16@gmail.com>, Peter Smith <smithpb2250@gmail.com>, Rahila Syed <rahilasyed90@gmail.com>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>, Önder Kalacı <onderkalaci@gmail.com>, japin <japinli@hotmail.com>, Michael Paquier <michael@paquier.xyz>, David Steele <david@pgmasters.net>, Craig Ringer <craig@2ndquadrant.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Amit Langote <amitlangote09@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>

Date: 2021-07-07T05:24:24Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Release cache tuple when no longer needed
- ed0fbc8e5ac9 15.0 landed
Add some additional tests for row filters in logical replication.
- ceb57afd3ce1 15.0 landed
Fix one of the tests introduced in commit 52e4f0cd47.
- cfb4e209ec15 15.0 landed
Allow specifying row filters for logical replication of tables.
- 52e4f0cd472d 15.0 landed
Move scanint8() to numutils.c
- cfc7191dfea3 15.0 cited
Replace Test::More plans with done_testing
- 549ec201d613 15.0 cited
Reduce relcache access in WAL sender streaming logical changes
- 6ce16088bfed 15.0 cited
Small cleanups related to PUBLICATION framework code
- c9105dd3660f 15.0 cited
Add a view to show the stats of subscription workers.
- 8d74fc96db5f 15.0 cited
Allow publishing the tables of schema.
- 5a2832465fd8 15.0 cited
Doc: improve documentation of CREATE/ALTER SUBSCRIPTION.
- 1882d6cca161 15.0 cited
Add PublicationTable and PublicationRelInfo structs
- 0c6828fa987b 15.0 cited
Remove unused argument "txn" in maybe_send_schema().
- 93d573d86571 15.0 cited
Add prepare API support for streaming transactions in logical replication.
- 63cf61cdeb7b 15.0 cited
Unify PostgresNode's new() and get_new_node() methods
- 201a76183e20 15.0 cited
Use l*_node() family of functions where appropriate
- 2b00db4fb0c7 15.0 cited
Add support for prepared transactions to built-in logical replication.
- a8fd13cab0ba 15.0 cited
Restore the portal-level snapshot after procedure COMMIT/ROLLBACK.
- ef9480509622 11.13 cited
Rename a parse node to be more general
- 91d1f2d30210 14.0 landed
Remove unused column atttypmod from initial tablesync query
- 4ad31bb2ef25 14.0 landed
SEARCH and CYCLE clauses
- 3696a600e229 14.0 cited

Attachments

v16-0005-Improve-row-filtering-performance.patch (application/octet-stream) patch v16-0005
graph-performance.PNG (image/png)

On Thu, Jul 1, 2021 at 10:43 AM Euler Taveira <euler@eulerto.com> wrote:
>
>
> Amit, thanks for rebasing this patch. I already had a similar rebased patch in
> my local tree. A recent patch broke your version v15 so I rebased it.
>

Hi,

I did some testing of the performance of the row filtering, in the
case of the publisher INSERTing 100,000 rows, using a similar test
setup and timing as previously used in the “commands_to_perf_test.sql“
script posted by Önder Kalacı.

I found that with the call to ExecInitExtraTupleSlot() in
pgoutput_row_filter(), then the performance of pgoutput_row_filter()
degrades considerably over the 100,000 invocations, and on my system
it took about 43 seconds to filter and send to the subscriber.
However, by caching the tuple table slot in RelationSyncEntry, this
duration can be dramatically reduced by 38+ seconds.
A further improvement can be made using this in combination with
Peter's plan cache (v16-0004).
I've attached a patch for this, which relies on the latest v16-0001
and v16-0004 patches posted by Peter Smith (noting that v16-0001 is
identical to your previously-posted 0001 patch).
Also attached is a graph (created by Peter Smith – thanks!) detailing
the performance improvement.

Regards,
Greg Nancarrow
Fujitsu Australia