Tom Lane wrote: > There is some debug output available from the ARC code, > but I dunno if its output is actually useful ;-). Try > > http://developer.postgresql.org/docs/postgres/runtime-config.html#GUC-DEBUG-SHARED-BUFFERS
"debug_shared_buffers (integer) Number of seconds between ARC reports. If set greater than zero, emit ARC statistics to the log every so many seconds. Zero (the default) disables reporting." It seems it doesn't really do, what it says. Output is only sent during query execution, no output is sent when no query is active, so it's really hard to say what happens to buffers during idle time. Aside from that I don't believe that the output can answer questions about the efficiency of bgwriter... DEBUG: ARC T1target= 194 B1len= 779 T1len= 180 T2len= 820 B2len= 208 DEBUG: ARC total = 99% B1hit= 18% T1hit= 6% T2hit= 75% B2hit= 0% DEBUG: ARC clean buffers at LRU T1= 180 T2= 820 Anyone? Regarding current default settings - at this page: http://developer.postgresql.org/~wieck/vacuum_cost/ Jan, you used different settings for tests here. Can you explain your point of view? bgwriter_delay = 50 (now default 200) bgwriter_percent = 2 (now default 1) bgwriter_maxpages = 200 (now default 100) Regards, Michael Paesold ---------------------------(end of broadcast)--------------------------- TIP 3: 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
