Re: Does VACUUM reorder tables on clustered indices - Mailing list pgsql-sql

From Alvaro Herrera
Subject Re: Does VACUUM reorder tables on clustered indices
Date
Msg-id 20051219042935.GA5692@surnet.cl
Whole thread Raw
In response to Re: Does VACUUM reorder tables on clustered indices  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-sql
Tom Lane escribió:
> Alvaro Herrera <alvherre@commandprompt.com> writes:
> > Note that while reordering, CLUSTER also gets rid of dead tuples, so if
> > you cluster you don't need to vacuum.
> 
> Just for the record, that behavior is seriously broken: it violates
> MVCC if any of the deleted tuples are still visible to anyone else.

Well, FWIW, the fact that the CLUSTER command exists at all is broken
IMHO ...  but meanwhile, are you suggesting that CLUSTER should be fixed
to retain tuples that are visible to running transactions?

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support


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