Horton
Menu

Re: Pgoutput not capturing the generated columns

Peter Smith <smithpb2250@gmail.com>

View thread
From: Peter Smith <smithpb2250@gmail.com>
To: vignesh C <vignesh21@gmail.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>, Michael Paquier <michael@paquier.xyz>, "Shinoda, Noriyoshi (SXD Japan FSIP)" <noriyoshi.shinoda@hpe.com>, Shubham Khanna <khannashubham1197@gmail.com>, Masahiko Sawada <sawada.mshk@gmail.com>, Rajendra Kumar Dangwal <dangwalrajendra888@gmail.com>, "pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>, "euler@eulerto.com" <euler@eulerto.com>
Date: 2025-01-17T01:53:06Z
Lists: pgsql-hackers 
Hi Vignesh.

Some review comments for v52-0001.

======
Commit message

1.
I guess the root cause is that in PG18 we decided to put the
"Generated columns" column to the left of the "Via Root" column
instead of to the right, and in doing so introduced a mistake ordering
the code.

The commit message can say that a bit more plainly -- e.g. you can
name those columns 'pubgencols' and 'pubviaroot' explicitly instead of
just referring to "the newly added column".

======
src/bin/psql/describe.c

describePublications:

2.
  if (has_pubgencols)
- printTableAddCell(&cont, PQgetvalue(res, i, 8), false, false);
- if (has_pubviaroot)
  printTableAddCell(&cont, PQgetvalue(res, i, 9), false, false);
+ if (has_pubviaroot)
+ printTableAddCell(&cont, PQgetvalue(res, i, 8), false, false);

It seems a bit tricky for the code to just have the PQgetvalue
hardwired indexes (8,9) reversed like that. I think at least this
reversal needs a comment to explain why it is done that way, so nobody
in future is tempted to change it and accidentally re-break this.

Maybe also, consider adding variables for those PQgetvalue indexes.
Maybe, something like this can work?

pubviaroot_idx = ncols;
pubgencols_idx = ncols + 1;

======
Kind Regards,
Peter Smith.
Fujitsu Australia

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Doc: Generated column replication.

  2. Rename pubgencols_type to pubgencols in pg_publication.

  3. Doc: Fix column name in pg_publication catalog.

  4. Fix buildfarm failure introduced by commit e65dbc9927.

  5. Change publication's publish_generated_columns option type to enum.

  6. Fix \dRp+ output when describing publications with a lower server version.

  7. Replicate generated columns when 'publish_generated_columns' is set.

  8. Doc: Update the behavior of generated columns in Logical Replication.

  9. Replicate generated columns when specified in the column list.

  10. Doc: Generated columns are skipped for logical replication.