Re: row filtering for logical replication

On Sat, Jan 29, 2022 at 11:31 AM Andres Freund <andres(at)anarazel(dot)de> wrote:
>
> Hi,
>
> Are there any recent performance evaluations of the overhead of row filters? I
> think it'd be good to get some numbers comparing:
>
> 1) $workload with master
> 2) $workload with patch, but no row filters
> 3) $workload with patch, row filter matching everything
> 4) $workload with patch, row filter matching few rows
>
> For workload I think it'd be worth testing:
> a) bulk COPY/INSERT into one table
> b) Many transactions doing small modifications to one table
> c) Many transactions targetting many different tables
> d) Interspersed DDL + small changes to a table
>

Here's the performance data results for scenario d:

HEAD "with patch no row filter" "with patch 0%" "row-filter-patch
25%" "row-filter-patch v74 50%" "row-filter-patch 75%"
"row-filter-patch v74 100%"
1 65.397639 64.414034 5.919732 20.012096 36.35911 49.412548 64.508842
2 65.641783 65.255775 5.715082 20.157575 36.957403 51.355821 65.708444
3 65.096526 64.795163 6.146072 21.130709 37.679346 49.568513 66.602145
4 65.173569 64.644448 5.787197 20.784607 34.465133 55.397313 63.545337
5 65.791092 66.000412 5.642696 20.258802 36.493626 52.873252 63.511428

The performance is similar to the other scenarios.
The script used is below:

CREATE TABLE test (key int, value text, value1 text, data jsonb,
PRIMARY KEY(key, value));

CREATE PUBLICATION pub_1 FOR TABLE test WHERE (key > 0); -- 100% allowed
CREATE PUBLICATION pub_1 FOR TABLE test WHERE (key > 250000); -- 75% allowed
CREATE PUBLICATION pub_1 FOR TABLE test WHERE (key > 500000); -- 50% allowed
CREATE PUBLICATION pub_1 FOR TABLE test WHERE (key > 750000); -- 25% allowed
CREATE PUBLICATION pub_1 FOR TABLE test WHERE (key > 1000000); -- 0% allowed

DO
$do$
BEGIN
FOR i IN 1..1000001 BY 4000 LOOP
Alter table test alter column value1 TYPE varchar(30);
INSERT INTO test VALUES(i,'BAH', row_to_json(row(i)));
Alter table test ALTER COLUMN value1 TYPE text;
UPDATE test SET value = 'FOO' WHERE key = i;
COMMIT;
END LOOP;
END
$do$;

regards,
Ajin Cherian
Fujitsu Australia