Re: Re: Name for new VACUUM

Tom Lane wrote:
> 
> Hannu Krosing <hannu@tm.ee> writes:
> > Just out of curiosity - does CLUSTER currently "practically rebuild
> > a tables representation" ?
> 
> CLUSTER currently *loses* most of a table's representation :-(.
> It needs work.

at least \h CLUSTER in psql seems to imply that it is OK to use CLUSTER
?

Do we have some indication of last CLUSTER command (like an OID column
of 
cluster index field) in pg_relation so that VACUUM caould make better 
decisions when moving tuples ?

> But since the whole point of CLUSTER is to physically rearrange the
> tuples of a table, it seems to me that it's in a different category
> from VACUUM anyway.

Another way to look at it is as "VACUUM LOCK AND PERFORM HEAVY
REARRANGEMENTS"

Or does the current implementation actually do the rearrangement by 
appending all out-of-index-order tuples to the end and _not_ clean up 
unused space requiring an additional vacuum after CLUSTER ?

--------------
Hannu