Re: Proposal: Select ... AS OF Savepoint

On Mon, 2007-11-05 at 11:58 +0530, Gokulakannan Somasundaram wrote:

>         The idea was to write a syncpoint every N seconds where we
>         record the
>         time and a snapshot of what's in progress. 
> 
> What exactly is getting recorded here? Will the Syncpoint be similar
> to the Undo Log at distinct intervals? 

Postgres needs to record the snapshot to allow visibility checks. There
is no Undo log; the database records themselves represent the logical
equivalent of an Undo log in other databases.

But as I said, I'm not working on this, so I'm not going into detailed
design anytime soon.

--  Simon Riggs 2ndQuadrant  http://www.2ndQuadrant.com