Eric Ridge <eeb...@gmail.com> writes: > What I'm seeing is that the ctid returned from this function isn't always > correct:
> # select ctid, foo(table) from table limit 10; > ctid | foo > -------+----------- > (0,1) | (19195,1) -- not correct! > (0,2) | (0,2) > (0,3) | (0,3) I suspect the tuple at (0,1) has been the subject of a failed update. Your problem here is that you're mistaking the t_ctid field of a tuple header for the tuple's address. It is not that; it's really just garbage normally, and is only useful to link forward to the next version of the row from an outdated tuple. I think we do initialize it to the tuple's own address during an INSERT, but either a completed or failed UPDATE would change it. I do not think there is any way to get the true address of a heap tuple out of a composite Datum manufactured from the tuple. Most of the other system columns can't be gotten from a composite Datum either, because of the field overlay in HeapTupleHeaderData's union t_choice. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers