Re: why there is not VACUUM FULL CONCURRENTLY?

On Mon, Jan 13, 2025 at 8:56 AM Michael Banck <mbanck(at)gmx(dot)net> wrote:
> Hi,
> On Sat, Jan 11, 2025 at 09:01:54AM -0500, Andrew Dunstan wrote:
> > On 2025-01-09 Th 8:35 AM, Alvaro Herrera wrote:
> > > Maybe we should have a new toplevel command. Some ideas that have been
> > > thrown around:
> > >
> > > - RETABLE (it's like REINDEX, but for tables)
> > > - ALTER TABLE <tab> SQUEEZE
> > > - SQUEEZE <table>
> > > - VACUUM (SQUEEZE)
> > > - VACUUM (COMPACT)
> > > - MAINTAIN <tab> COMPACT
> > > - MAINTAIN <tab> SQUEEZE
>
> I don't like any of them a lot :-/
>

Agreed, though I do believe there would be a positive gain from
eliminating the overloaded CLUSTER term.

> > COMPACT tablename ...
>
> That sounds like it would compress content rather than just rewrite it
> normally to get rid of bloat.
>
> I think REORG (or REPACK, but that has not history elsewhere) would fit
> best, we don't need to emulate the myriad of DB2 options...
>

I would like REPACK if I didn't believe it would lead to confusion
with pg_repack (which, afaict, seems to have better performance
characteristics, so will probably hang around).

Actually, I wonder if we are too focused on the idea this is a
vaccum/bloat related tool. The original idea behind CLUSTER was not
related to vacuum or bloat management, but performance. There are
other reasons to want to rewrite a table as well (think dropped
columns or new column defaults). Is ALTER TABLE <table> REWRITE an
option? Current needed options would be for clustering or running
concurrently, but even without those options sometimes you just want
to rewrite the table, and this is probably the most straightforward
than making something up.

Robert Treat
https://xzilla.net