[flossly]

Years ago I heard Oracle's db had an edge on PG when it comes to DELETEs. I guess that's still the case...

[mike_hearn]

Oracle has ALTER TABLE [name] MOVE ONLINE INCLUDING ROWS [predicates]. This is basically what you want - it keeps only the data matching the predicate, it's efficient and it works without disrupting the app. That might be the edge you heard about.

[asgeirn]

Also ALTER TABLE DROP PARTITION