On Mon, 2007-12-17 at 08:47 -0500, Andrew Dunstan wrote: > This strikes me as such a corner case that it's likely not to be worth it. > > If you really want to save space along these lines, one better place to > start might be mutable with column ordering - see > http://archives.postgresql.org/pgsql-hackers/2006-12/msg00983.php . That > would mean that we would be able to move nullable columns physically to > the tail which in turn might help this suggestion have more effect.
Could be a good idea. Currently on a 64-bit system we occupy 23 bytes for row header, so any table with more than 8 columns will cause the null bitmap to overflow and for us to use another 8 bytes. OP's idea could avoid that in many cases, so the saving isn't 1 byte it is fairly frequently going to be an 8 byte saving. -- Simon Riggs 2ndQuadrant http://www.2ndQuadrant.com ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
