Martijn van Oosterhout <[EMAIL PROTECTED]> writes: > On Wed, Nov 05, 2008 at 09:41:52PM +0000, Gregory Stark wrote: >> "Robert Haas" <[EMAIL PROTECTED]> writes: >> >> >> Problem is how to move tuple from page to another and keep indexes in >> >> sync. >> >> One solution is to perform some think like "update" operation on the >> >> tuple. >> >> But you need exclusive lock on the page and pin counter have to be zero. >> >> And >> >> question is where it is safe operation. >> > >> > But doesn't this problem go away if you do it in a transaction? You >> > set xmax on the old tuple, write the new tuple, and add index entries >> > just as you would for a normal update. >> >> But that doesn't actually solve the overflow problem on the old page... > > Sure it does. You move just enough tuples that you can convert the page > without an overflow.
setting the xmax on a tuple doesn't "move" the tuple -- Gregory Stark EnterpriseDB http://www.enterprisedb.com Ask me about EnterpriseDB's RemoteDBA services! -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
