On Sun, Apr 21, 2024 at 6:45 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Ron Johnson <ronljohnsonjr(at)gmail(dot)com> writes:
> > Why is VACUUM FULL recommended for compressing a table, when CLUSTER does
> > the same thing (similarly doubling disk space), and apparently runs just
> as
> > fast?
>
> CLUSTER makes the additional effort to sort the data per the ordering
> of the specified index. I'm surprised that's not noticeable in your
> test case.
>
Clustering on a completely different index was also 44 seconds.