Re: [PATCH] vacuumlo: print the number of large objects going to beremoved - Mailing list pgsql-hackers

From Michael Paquier
Subject Re: [PATCH] vacuumlo: print the number of large objects going to beremoved
Date
Msg-id 20190906072940.GG1608@paquier.xyz
Whole thread Raw
In response to Re: [PATCH] vacuumlo: print the number of large objects going to beremoved  ("Daniel Verite" <daniel@manitou-mail.org>)
Responses Re: [PATCH] vacuumlo: print the number of large objects going to be removed
List pgsql-hackers
On Wed, Jul 17, 2019 at 01:31:05PM +0200, Daniel Verite wrote:
> The tab width should be 4. Please have a look at
> https://www.postgresql.org/docs/current/source-format.html
> It also explains why opportunistic reformatting is futile, anyway:

-       char       *schema,
-                  *table,
-                  *field;
+       char    *schema,
+           *table,
+           *field;
The patch has some noise.  For something of this size, I don't think
that it is an issue though ;)

> It might be useful to display the progress report in the loop, but
> it appears that even when there's nothing to remove, vacuumlo is
> likely to take a long time, because of the method it uses:
>
> [stuff]
>
> That might be much faster than #1 and #2, especially in the case when
> there's only one SELECT in that subquery and no UNION ALL is even
> necessary.

Sure.  However do we need to introduce this much complication as a
goal for this patch though whose goal is just to provide hints about
the progress of the work done by vacuumlo?  I have just looked at the
latest patch and the thing is actually much more simple than what I
recalled.

One comment I have is if we should also report in the progress not
only the percentage, but also the raw numbers of deleted entries with
the total numbers of entries to delete.  Timur, what do you think?
--
Michael

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