Re: Rollback in Postgres

On Fri, 2008-07-11 at 11:21 -0600, Scott Marlowe wrote:
> rollback after commit

Are you sure? 

Personally I don't think its viable. If it really does that it will
would also need to rollback all transactions whose changes depend upon
the earlier transaction. It would also need to track transactions that
read data changed by an earlier transaction and then makes changes to
the database. It's got no way to track that without extensive and costly
additional infrastructure, since after transaction commit row locking
information can be cleaned up by read-only transactions accessing those
changed data blocks.

Flashback query allows reading data as it was at a certain point in the
past. We might one day provide that, but undoing individual transactions
isn't ever going to be feasible, without unknowable risk.

Not jumping on you, just think their marketing is ahead of the reality.

-- Simon Riggs           www.2ndQuadrant.comPostgreSQL Training, Services and Support