On Sat, 2002-05-11 at 11:24, Tom Lane wrote: > Hannu Krosing <[EMAIL PROTECTED]> writes: > > Was it not the case that lazy vacuum had problems freeing tuples that > > have toasted fields ? > > News to me if so. > > regards, tom lane
It looks like this may in fact be the case. I performed a number of tests using the previous setup, but shortening the row length and using pg_attribute.attstorage to untoast the text field for some of the tests. The difference is striking. The behaviour of the untoasted case is pretty much as expected : the database grows a bit and then stabilizes at some size. However I could not get any size stabilization in the toasted case. Here are (some) of my test results : Fsm Siz |Threads|Toast |Init(M)|End (M)|Stable |Stable Time(h) |Run Time(h) 20000 | 2 |Y | 166 | 380 | N | - |17 60000 | 2 |Y | 166 | 430 | N | - |20 10000 | 2 |N | 162 | 235 | Y | 0.5 |1 20000 | 2 |N | 166 | 235 | Y | 0.5 |13 60000 | 2 |N | 166 | 235 | Y | 0.5 |13 legend : Fsm Siz = max_fsm_pages Threads = no. update threads Toast = whether body field was toasted Init = initial database size End = final database size Stable = whether database growth had stopped Stable Time = when stable size was achieved Run Time = length of test run (excluding initial database population) Average vacuum time = 300s Typical (1 thread) entire table update time = 2000s Row length = 7.5K The scripts I used are here : http://homepages.slingshot.co.nz/~markir/tar/test/spin.tar.gz At this point I am wondering about sending this in as a bug report - what do you think ? regards, Mark ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/users-lounge/docs/faq.html
