Horton

Re: Minimal logical decoding on standbys

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Andres Freund <andres@anarazel.de>
Cc: Amit Khandekar <amitdkhan.pg@gmail.com>, tushar <tushar.ahuja@enterprisedb.com>, Petr Jelinek <petr.jelinek@2ndquadrant.com>, Craig Ringer <craig@2ndquadrant.com>, Petr Jelinek <petr@2ndquadrant.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2019-07-10T03:51:23Z
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.

On Tue, Jul 9, 2019 at 11:14 PM Andres Freund <andres@anarazel.de> wrote:
> > +                     if (xlrec->wal_level < WAL_LEVEL_LOGICAL)
> > +                             ereport(ERROR,
> > +                                             (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
> > +                                              errmsg("logical decoding on standby requires "
> > +                                                             "wal_level >= logical on master")));
> > +                     break;
>
> Hm, this strikes me as a not quite good enough error message (same in
> other copies of the message). Perhaps something roughly like "could not
> continue with logical decoding, the primary's wal level is now too low
> (%u)"?

For what it's worth, I dislike that wording on grammatical grounds --
it sounds like two complete sentences joined by a comma, which is poor
style -- and think Amit's wording is probably fine.  We could fix the
grammatical issue by replacing the comma in your version with the word
"because," but that seems unnecessarily wordy to me.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
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