*1) Show how you have set up the publishers and subscribers.*
We have configured logical replication between PostgreSQL 11 (publisher)
and PostgreSQL 16 (subscriber).
Publisher: PostgreSQL 11 with wal_level=logical, max_replication_slots=20,
and publication created for all tables (FOR ALL TABLES).
Subscriber: PostgreSQL 16 with max_logical_replication_workers=16,
max_sync_workers_per_subscription=8, connected through a subscription to
replicate all tables.
select * from pg_publication;
pubname | pubowner | puballtables | pubinsert | pubupdate | pubdelete |
pubtruncate
-----------+----------+--------------+-----------+-----------+-----------+-------------
test_v_pub | 10 | t | t | t | t |
t
(1 row)
select * from pg_replication_slots ;
slot_name | plugin | slot_type | datoid
| database | temporary | active | active_pid | xmin | catalog_xmin |
restart_lsn | confirmed_flush_lsn
-------------------------------------------+----------+-----------+--------+----------+-----------+--------+------------+------+--------------+----------------+---------------------
vahan_sub | pgoutput | logical | 16468
| test_v | f | t | 3722767 | | 3146687395 |
20538/7D039948 | 20538/7D045790
pg_120870_sync_94301_7567666078127625550 | pgoutput | logical | 16468
| test_v | f | f | | | 3146687395 |
20538/71C4FD28 | 20538/71C4FD60
pg_120870_sync_93499_7567666078127625550 | pgoutput | logical | 16468
| test_v | f | f | | | 3146687395 |
20538/7D039948 | 20538/7D039980
pg_120870_sync_99121_7567666078127625550 | pgoutput | logical | 16468
| test_v | f | f | | | 3146687395 |
20538/6F290C88 | 20538/6F290CC0
pg_120870_sync_108854_7567666078127625550 | pgoutput | logical | 16468
| test_v | f | f | | | 3146687395 |
20538/7C6B5FD0 | 20538/7C6B6020
pg_120870_sync_93451_7567666078127625550 | pgoutput | logical | 16468
| test_v | f | f | | | 3146687395 |
20538/7D0359A8 | 20538/7D0359E0
pg_120870_sync_94589_7567666078127625550 | pgoutput | logical | 16468
| test_v | f | f | | | 3146687395 |
20538/4C0001E8 | 20538/4C000220
pg_120870_sync_98225_7567666078127625550 | pgoutput | logical | 16468
| test_v | f | f | | | 3146687395 |
20538/6F290DA0 | 20538/6F290DD8
pg_120870_sync_96438_7567666078127625550 | pgoutput | logical | 16468
| test_v | f | f | | | 3146687395 |
20538/75CE4120 | 20538/75CE4158
pg_120870_sync_93469_7567666078127625550 | pgoutput | logical | 16468
| test_v | f | f | | | 3146687395 |
20538/7D00E0B0 | 20538/7D00E0E8
pg_120870_sync_94277_7567666078127625550 | pgoutput | logical | 16468
| test_v | f | f | | | 3146687395 |
20538/4C000178 | 20538/4C0001B0
pg_120870_sync_109085_7567666078127625550 | pgoutput | logical | 16468
| test_v | f | f | | | 3146687395 |
20538/7B72CFE8 | 20538/7B72D020
pg_120870_sync_109110_7567666078127625550 | pgoutput | logical | 16468
| test_v | f | f | | | 3146687395 |
20538/7AE3B078 | 20538/7AE3B0B0
pg_120870_sync_99247_7567666078127625550 | pgoutput | logical | 16468
| test_v | f | f | | | 3146687395 |
20538/4C0001B0 | 20538/4C0001E8
pg_120870_sync_103454_7567666078127625550 | pgoutput | logical | 16468
| test_v | f | f | | | 3146687395 |
20538/7D0002F0 | 20538/7D000328
pg_120870_sync_96317_7567666078127625550 | pgoutput | logical | 16468
| test_v | f | f | | | 3146687395 |
20538/71C59D20 | 20538/71C59D58
pg_120870_sync_107790_7567666078127625550 | pgoutput | logical | 16468
| test_v | f | f | | | 3146687395 |
20538/7A4102F0 | 20538/7A410328
pg_120870_sync_98730_7567666078127625550 | pgoutput | logical | 16468
| test_v | f | f | | | 3146687395 |
20538/6F00CE40 | 20538/6F00CE78
pg_120870_sync_93488_7567666078127625550 | pgoutput | logical | 16468
| test_v | f | f | | | 3146687395 |
20538/7CF2C4F0 | 20538/7CF2C528
pg_120870_sync_103457_7567666078127625550 | pgoutput | logical | 16468
| test_v | f | f | | | 3146687395 |
20538/6F127188 | 20538/6F1271C0
(20 rows)
postgres=# select * from pg_subscription;
-[ RECORD 1
]-------+---------------------------------------------------------------------
oid | 120870
subdbid | 91683
subskiplsn | 0/0
subname | test_v_sub
subowner | 10
subenabled | t
subbinary | f
substream | f
subtwophasestate | d
subdisableonerr | f
subpasswordrequired | t
subrunasowner | f
subconninfo | host=xyz port=5432 user=postgres password=test
dbname=test_v
subslotname | test_v_sub
subsynccommit | off
subpublications | {test_v_pub}
suborigin | any
*2) Are you trying to replicate everything at once or a table or subsetof
tables at a time?*
We are replicating all tables at once (full database-level replication),
not table-by-table.
*3) How active is the source database?*
The source database is highly active, with continuous transactions and
heavy write activity across large tables.
Thanks & Regards
Krishna.
On Thu, 6 Nov 2025 at 23:53, Adrian Klaver <[email protected]>
wrote:
> On 11/6/25 09:04, Bala M wrote:
> >
> > Hi Adrian, Thank you for your response. Please find the requested
> > details below:
> >
>
> > Since you have already started is that not already to late for this?
> >
> > Yes We are currently in the *testing phase* and validating with the
> > above parameters. However, the replication process has been *extremely
> > slow — it’s been running for the past 5 days* with limited progress.
>
> 1) Show how you have set up the publishers and subscribers.
>
> 2) Are you trying to replicate everything at once or a table or subset
> of tables at a time?
>
> 3) How active is the source database?
>
> >
> > Any specific tuning recommendations or best practices to improve
> > performance at this stage would be greatly appreciated.
> >
> >
> > Thanks & Regards
> > Krishna.
> >
> >
>
> --
> Adrian Klaver
> [email protected]
>
