On Thu, Mar 10, 2011 at 12:31 PM, hans wulf <lo...@gmx.net> wrote: > I don't know the postgres code, but I don't thing it is a big deal, not to > care about consistancy. The code for executing such a query should be quite > basic, because no MVCC-Stuff has to be done.
I remember I used to think this would be simple -- just return all rows regardless of visibility. However I later learned things were more complex than that. You probably want to return the latest version of any row regardless of whether it's committed but *not* return two or more copies of the same row which would really make the results entirely meaningless. That alone would make it prohibitively hard to do. I think I remember issues with potentially running into old rows that don't even match the current definition of the table. That would potentially cause you to crash or output garbage. However offhand I don't see how that would be possible so perhaps I'm misremembering this issue. -- greg -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
