On a few occasions I've come across vacuums that result in more pages stored than needed, ie:
INFO: free space map: 81 relations, 235349 pages stored; 220672 total pages needed DETAIL: Allocated FSM size: 1000 relations + 2000000 pages = 11817 kB shared memory. I see that PrintFreeSpaceMapStatistics holds an exclusive lock both while it counts actual space usage and while it grabs the info used to calculate pages needed, so it's not a problem of part of that data changing while the count happens. I don't think that the issue is PrintFreeSpaceMapStatistics not accounting for the fact that each relation is guaranteed CHUNKPAGES, either (I believe sumRequests + numRels handles that). Any ideas as to what else could cause this problem? If it can't be figured out, should PrintFreeSpaceMapStatistics at least ensure that needed >= storedPages? As it stands right now, users need to do that math in their head when sizing max_fsm_pages, which is a bit confusing. Another question... while looking through the code, I see that any GetPageWithFreeSpace ensures that an entry for the relation it was called for exists by calling create_fsm_rel. create_fsm_rel will create the entry if needed and put it at the head of the FSM. Doesn't this mean that a lot of repeated requests to create new tables could 'blow out' a substantial chunk of the FSM? Or more likely, some periodic process that updates a large number of tables that don't normally get other requests for free space would have the same effect. I realize that improving this would probably involve a non-trivial amount of work, so maybe a good compromise would be logging a warning anytime a relation is dropped due to hitting max_fsm_relations. -- Jim C. Nasby, Sr. Engineering Consultant [EMAIL PROTECTED] Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461 ---------------------------(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
