Hullo, here's one of those dreadful touchy-feely hand-waving problems. Our 5-node 8.1.3 Slony system has just started taking /much/ longer to VACUUM ANALYZE.. The data set has not increased more than usual (nightly backups stand at 1.3GB, growing by 10MB per day), and no configuration has changed on the machines. Nodes 2 and 3 take only the tables necessary to run our search (10 out of the full 130) and are much lighter (only 7GB on disk cf. 30GB for the full master) , yet the nightly VACUUM FULL has jumped from 2 hours to 4 in the space of one day! Like I say, no config changes, no reboots / postmaster restarts, no extra processes, and every machine has a comfortable overhead of free page slots + relations.
