Horton

Re: Minimal logical decoding on standbys

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Jeff Davis <pgsql@j-davis.com>
Cc: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com>, Robert Haas <robertmhaas@gmail.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>
Date: 2023-04-02T22:29:04Z
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 →

  1. Reduce the log level in 035_standby_logical_decoding.pl.

  2. 035_standby_logical_decoding: Add missing waits for replication

  3. For cascading replication, wake physical and logical walsenders separately

  4. Handle logical slot conflicts on standby

  5. Support invalidating replication slots due to horizon and wal_level

  6. Prevent use of invalidated logical slot in CreateDecodingContext()

  7. Replace replication slot's invalidated_at LSN with an enum

  8. Pass down table relation into more index relation functions

  9. Assert only valid flag bits are passed to visibilitymap_set()

  10. Remove unused _bt_delitems_delete() argument.

  11. Add xl_btree_delete optimization.

Hi,

On 2023-04-02 15:15:44 -0700, Jeff Davis wrote:
> On Sun, 2023-04-02 at 14:35 -0700, Andres Freund wrote:
> > Why not offer a function to add a CV to a WES? It seems somehow odd
> > to require
> > going through condition_variable.c to create a WES.
> 
> I agree that it's a bit odd, but remember that after waiting on a CV's
> latch, it needs to re-insert itself into the CV's wait list.
> 
> A WaitEventSetWait() can't do that, unless we move the details of re-
> adding to the wait list into latch.c. I considered that, but latch.c
> already implements the APIs for WaitEventSet and Latch, so it felt
> complex to also make it responsible for ConditionVariable.

I agree that the *wait* has to go through condition_variable.c, but it doesn't
seem right that creation of the WES needs to go through condition_variable.c.

The only thing that ConditionVariableEventSleep() seems to require is that the
WES is waiting for MyLatch. You don't even need a separate WES for that, the
already existing WES should suffice.

Greetings,

Andres Freund