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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Ron Johnson <ronljohnsonjr@gmail.com>
cc: pgsql-general <pgsql-general@postgresql.org>
Subject: Re: CLUSTER vs. VACUUM FULL
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Comments: In-reply-to Ron Johnson <ronljohnsonjr@gmail.com>
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Ron Johnson <ronljohnsonjr@gmail.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.

			regards, tom lane