"Ruediger Herrmann" <ruediger.herrmann@gmx.de> writes:
> has anyone implemented row versions/timestamps in PostgreSQL or any
> thoughts on this?
> Did I hit the right term? What I want to achieve is optimistic
> concurrency beyound transaction boundaries. When retrieving data
> I would also retrieve the row version and later on, in a different
> transaction, before updating the data, I could check if was unchanged.
You could use the xmin system column for this.
regards, tom lane