>From http://developer.postgresql.org/todo.php:
Maintain a map of recently-expired rows This allows vacuum to reclaim free space without requiring a sequential scan On Sat, Jan 22, 2005 at 12:20:53PM -0500, Greg Stark wrote: > Dawid Kuroczko <[EMAIL PROTECTED]> writes: > > > Quick thought -- would it be to possible to implement a 'partial VACUUM' > > per analogiam to partial indexes? > > No. > > But it gave me another idea. Perhaps equally infeasible, but I don't see why. > > What if there were a map of modified pages. So every time any tuple was marked > deleted it could be marked in the map as modified. VACUUM would only have to > look at these pages. And if it could mark as free every tuple that was marked > as deleted then it could unmark the page. > > The only downside I see is that this could be a source of contention on > multi-processor machines running lots of concurrent update/deletes. > > -- > greg > > > ---------------------------(end of broadcast)--------------------------- > TIP 6: Have you searched our list archives? > > http://archives.postgresql.org > -- Jim C. Nasby, Database Consultant [EMAIL PROTECTED] Give your computer some brain candy! www.distributed.net Team #1828 Windows: "Where do you want to go today?" Linux: "Where do you want to go tomorrow?" FreeBSD: "Are you guys coming, or what?" ---------------------------(end of broadcast)--------------------------- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match