Re: pgsql: reindexdb: Add the index-level REINDEX with multiple jobs

On 2025-Mar-09, Alexander Korotkov wrote:

> After second thought it's not so hard to fix.  The attached patch does
> it by putting REINDEX commands related to the same table into a single
> SQL statement.  Possibly, that could be better than revert given we
> need to handle compatibility.  What do you think?

Oh, this is an egg of Columbus solution, I like it.  It seems to work as
intended on a quick test.  Please add some commentary to run_reindex_command.

Maybe another, possibly better way to do this would be to use libpq
pipeline mode, sending all the commands for a table in one pipeline
instead of a single command.  The advantage of this would be that
server-side log entries for each command would be separate, and they
wouldn't appear clumped together in pg_stat_activity and so on.
However, this would require more invasive changes, so it might be better
to leave that for a future project -- it's certainly a harder sell for
such a change to be backpatched.  So I'm +1 on your current patch for 17
and master.

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/
"Puedes vivir sólo una vez, pero si lo haces bien, una vez es suficiente"