Re: CLUSTER and MVCC - Mailing list pgsql-hackers

From Gregory Stark
Subject Re: CLUSTER and MVCC
Date
Msg-id 87fy8e4mgd.fsf@stark.xeocode.com
Whole thread Raw
In response to Re: CLUSTER and MVCC  (Csaba Nagy <nagy@ecircle-ag.com>)
Responses Re: CLUSTER and MVCC  (Csaba Nagy <nagy@ecircle-ag.com>)
Re: CLUSTER and MVCC  (Alvaro Herrera <alvherre@commandprompt.com>)
List pgsql-hackers
"Csaba Nagy" <nagy@ecircle-ag.com> writes:

> Wouldn't be possible to do it like Simon (IIRC) suggested, and add a
> parameter to enable/disable the current behavior, and use the MVCC
> behavior as default ?

Doing it in CLUSTER would be weird. However perhaps it would be useful to have
some sort of stand-alone tool that just bumped all the xmin/xmax's. It would
have to be super-user-only and carry big warning labels saying it breaks MVCC.

But it would be useful any time you have a table that you want to exempt a
particular table from serializable snapshots. Basically a per-table way to
force a read-committed snapshot on. Though, actually it's not quite a
read-committed snapshot is it? Anyone using an old serializable snapshot will
see what, no tuples at all?

--  Gregory Stark EnterpriseDB          http://www.enterprisedb.com


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