Parallel Query Is Getting Better And Better

Back in early November, I reported that the first version of parallel sequential scan had been committed to PostgreSQL 9.6.  I'm pleased to report that a number of significant enhancements have been made since then.  Of those, the two that are by the far the most important are that we now support parallel joins and parallel aggregation - which means that the range of queries that can benefit from parallelism is now far broader than just sequential scans.

No More Full-Table Vacuums

I just committed a very important patch to PostgreSQL.  The short summary for the patch is "Don't vacuum all-frozen pages." and it follows up on a patch I committed last week, whose short summary was "Change the format of the VM fork to add a second bit per page."  This led Andres Freund to respond with a one word email: "Yeha!"