Re: Improve the concurency of vacuum full table and select statement on the same relation

On Thu, Oct 15, 2015 at 8:28 PM, Jim Nasby <Jim(dot)Nasby(at)bluetreble(dot)com> wrote:
> It's just how the authors of pg_repack decided to handle it. It seems pretty
> reasonable, since you probably don't want an errant DDL statement to cause
> the rollback of hours or days of pg_repack work.
>
> Ultimately, I don't think you'll find many people interested in working on
> this, because the whole goal is to never need VACUUM FULL or pg_repack. If
> you're clustering just for the sake of clustering, that has it's own set of
> difficulties that should be addressed.

I think the topic of online table reorganization is a pretty important
one, actually. That is a need that we have had for a long time,
creates serious operational problems for users, and it's also a need
that is not going away. I think the chances of eliminating that need
completely, even if we rearchitected or heap storage, are nil.

I think the bigger issue is that it's a very hard problem to solve.
pg_repack is one approach, but I've heard more than one person say
that, as C-3PO said about the asteroid, it may not be entirely stable.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company