Re: Minimal logical decoding on standbys

Bertrand Drouvot <bertranddrouvot.pg@gmail.com>

From: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com>

To: Amit Kapila <amit.kapila16@gmail.com>

Cc: Andres Freund <andres@anarazel.de>, Robert Haas <robertmhaas@gmail.com>, Jeff Davis <pgsql@j-davis.com>, Thomas Munro <thomas.munro@gmail.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, Ibrar Ahmed <ibrar.ahmad@gmail.com>, Amit Khandekar <amitdkhan.pg@gmail.com>, fabriziomello@gmail.com, tushar <tushar.ahuja@enterprisedb.com>, Rahila Syed <rahila.syed@2ndquadrant.com>, pgsql-hackers <pgsql-hackers@postgresql.org>, Melanie Plageman <melanieplageman@gmail.com>

Date: 2023-04-04T14:53:31Z

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 →

Reduce the log level in 035_standby_logical_decoding.pl.
- 3034dc56ef4b 16.0 landed
035_standby_logical_decoding: Add missing waits for replication
- 57411c82ce86 16.0 landed
For cascading replication, wake physical and logical walsenders separately
- e101dfac3a53 16.0 landed
Handle logical slot conflicts on standby
- 26669757b6a7 16.0 landed
Support invalidating replication slots due to horizon and wal_level
- be87200efd93 16.0 landed
Prevent use of invalidated logical slot in CreateDecodingContext()
- 4397abd0a2af 16.0 landed
Replace replication slot's invalidated_at LSN with an enum
- 15f8203a5975 16.0 landed
Pass down table relation into more index relation functions
- 61b313e47eb9 16.0 landed
Assert only valid flag bits are passed to visibilitymap_set()
- a88a18b1250b 16.0 landed
Remove unused _bt_delitems_delete() argument.
- dc43492e46c7 14.0 cited
Add xl_btree_delete optimization.
- d2e5e20e5711 13.0 cited

Attachments

v59-0006-Doc-changes-describing-details-about-logical-dec.patch (text/plain) patch v59-0006
v59-0005-New-TAP-test-for-logical-decoding-on-standby.patch (text/plain) patch v59-0005
v59-0004-Fixing-Walsender-corner-case-with-logical-decodi.patch (text/plain) patch v59-0004
v59-0003-Allow-logical-decoding-on-standby.patch (text/plain) patch v59-0003
v59-0002-Arrange-for-a-new-pg_stat_database_conflicts-and.patch (text/plain) patch v59-0002
v59-0001-Handle-logical-slot-conflicts-on-standby.patch (text/plain) patch v59-0001

Hi,

On 4/4/23 3:43 PM, Amit Kapila wrote:
> On Tue, Apr 4, 2023 at 6:05 PM Drouvot, Bertrand
> 
> I think we might want to consider slot's effective_xmin instead of
> data.xmin as we use that to store xmin_horizon when we build the full
> snapshot.
> 

Oh, I did not know about the 'effective_xmin' and was going to rely only on the catalog xmin.

Reading the comment in the ReplicationSlot struct about the 'effective_xmin' I do think it makes sense to use it
(instead of data.xmin).

Please find attached v59 doing so.

Regards,

-- 
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com