Idea for debug/recovery snapshots

On Tue, Nov 12, 2013 at 08:39:35PM -0500, Bruce Momjian wrote:
> > My specific wording is incoherent mostly because it really belongs to a
> > larger corpus that currently exists only in my head.
> 
> Oh, OK, it sounds fine.  The user really doesn't choose what timeline to
> see --- rather, it is the current xid at the time they take their
> snapshot and other running xids that controls that.  You can control
> your transaction isolation level, but that only controls how often you
> take snapshots.

[ moved to hackers ]

Actually, it would be possible to allow snapshots that are equal to the
earliest active snapshot for the current database.  I don't think it
would be useful in production, but perhaps for debugging or some
disaster recovery.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + Everyone has their own god. +