9.0 VACUUM FULL vs. ALTER TABLE?

От:

Noah Misch <noah@leadboat.com>

Дата:

6 марта 2010 г. в 00:27:12

I understand that 9.0 will have a new implementation of VACUUM FULL that follows
a rewrite strategy like CLUSTER or ALTER TABLE.  What differences will remain
between VACUUM FULL and a no-op ALTER TABLE that rewrites?  Will there remain
situations in which to prefer the latter, or will it essentially boil down to
two different spellings of the same request?

CREATE TABLE t (x int);
VACUUM FULL t;
-- versus
ALTER TABLE t ALTER x TYPE int;

Thanks,
nm

Re: 9.0 VACUUM FULL vs. ALTER TABLE?

От:

Tom Lane <tgl@sss.pgh.pa.us>

Дата:

6 марта 2010 г. в 11:27:45

Noah Misch  writes:
> I understand that 9.0 will have a new implementation of VACUUM FULL that follows
> a rewrite strategy like CLUSTER or ALTER TABLE.  What differences will remain
> between VACUUM FULL and a no-op ALTER TABLE that rewrites?  Will there remain
> situations in which to prefer the latter,

No.  They're pretty much the same.

			regards, tom lane