Zdenek Kotala wrote: > Heikki Linnakangas napsal(a): > >> It would be >> simple to update the FSM at every heap insert and update record, but >> that then might be an unacceptable amount of overhead at recovery. Also, >> the index FSM is not yet updated during recovery. > > I expect locking problems specially on small tables where FSM has only one > level > instead slower recovery. Maybe background writer could update FSM info, but it > breaks modularity and It could bring problems during checkpoints.
Recovery is single-threaded (for the lack of a better word) anyway, so there can't be other backends competing for the locks. Background writer is one option. One option is to update the FSM if there's less than X% of free space on the page left after the insert/update. That would be similar to the rule we use during normal operation, which is to update the FSM whenever the target page fills up and we have to get a new page from the FSM. -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
