On Fri, 2006-07-21 at 15:49, Erik Jones wrote: > Scott Marlowe wrote: > > > > I'd use regular cronned vacuums on the tables that you know grown a lot > > (or just hit the whole db and not worry about it) and run occasional > > vacuum verbose / vacuum full verbose by hand to see if you have problems > > with your Free Space Map being too small. > > > Awesome! Thanks, guys, for all of your input/advice. That's pretty > much how I thought stuff worked after reading the docs but was > confused/misled by other inputs. With regards to the Free Space Map and > max_fsm_relations: is using the value of "SELECT COUNT(*) FROM > pg_class;" plus some room for growth a good way to set that?
I always use vacuum verbose to see that. At the end, it'll have a part that looks like this: INFO: free space map: 35 relations, 18903 pages stored; 17504 total pages needed DETAIL: Allocated FSM size: 5000 relations + 100000 pages = 894 kB shared memory. VACUUM So, on this machine, we can handle 5000 relations of 100,000 total pages, and we're only uses the space of 35 relations and ~20,000 pages. If the pages needed exceeds the allocated size, you've got problems. You've got to run the database for a while to see what the state will be like over time. ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
