Excerpts from Patrick Donlin's message of jue jul 15 11:12:53 -0400 2010:
> I'll read over that wiki entry, but for now here is the EXPLAIN ANALYZE output assuming I did it correctly. I have
runvacuumdb --full --analyze, it actually runs as a nightly cron job.
These plans seem identical (though the fact that the leading whitespace
was trimmed means it's untrustworthy -- please in the future send them
as text attachments instead so that your mailer doesn't interfere with
formatting). The 8.4 plan is even a full second faster, according to
the "total runtime" line.
The slowness could've been caused by caching effects ...