Robert Haas wrote: > To implement this in PostgreSQL, I believe we would need support for > UNDO.
> - Reading a page that has been recently modified gets significantly > more expensive; it is necessary to read the associated UNDO entries > and do a bunch of calculation that is significantly more complex than > what is required today. As others have said, that is the main drawback. Also, and related to this, ROLLBACK would become an expensive operation. Yours, Laurenz Albe -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers