On Sun, Jan 21, 2007 at 11:39:45AM +0000, Heikki Linnakangas wrote: > Russell Smith wrote: > >Strange idea that I haven't researched, Given Vacuum can't be run in a > >transaction, it is possible at a certain point to quit the current > >transaction and start another one. There has been much chat and now a > >TODO item about allowing multiple vacuums to not starve small tables. > >But if a big table has a long running vacuum the vacuum of the small > >table won't be effective anyway will it? If vacuum of a big table was > >done in multiple transactions you could reduce the effect of long > >running vacuum. I'm not sure how this effects the rest of the system > >thought. > > That was fixed by Hannu Krosing's patch in 8.2 that made vacuum to > ignore other vacuums in the oldest xmin calculation. And IIRC in 8.1 every time vacuum finishes a pass over the indexes it will commit and start a new transaction. That's still useful even with Hannu's patch in case you start a vacuum with maintenance_work_mem too small; you can abort the vacuum some time later and at least some of the work it's done will get committed. -- Jim Nasby jim@xxxxxxxxx EnterpriseDB http://enterprisedb.com 512.569.9461 (cell)
