> > Back to PostgreSQL, when a vacuum is issued, the old deleted rows are > > removed. This can be done with the autovacuum feature or manually. > > > > -Does vacuum make sure there are no long running queries referencing the > > deleted rows before it attempts to remove the old rows? > > It does. > > > -With autovacuum, does it skip these rows still being referenced in a > > transaction or does it wait? > > It skips them, the idea being that a future vacuum will remove them. > Awesome. In a large data warehouse, the snapshot too old error is very annoying and I'm glad PostgreSQL is superior to Oracle in this regard. :) Jon
