Re: A bug in mapping attributes in ATExecAttachPartition()

On Wed, Jul 26, 2017 at 9:50 PM, Amit Langote
<Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp> wrote:
> At least patch 0001 does address a bug. Not sure if we can say that 0002
> addresses a bug; it implements a feature that might be a
> nice-to-have-in-PG-10.

I think 0001 is actually several fixes that should be separated:

- Cosmetic fixes, like renaming childrels to attachRel_children,
adding a period after "Grab a work queue entry", and replacing the if
(skip_validate) / if (!skip_validate) blocks with if (skip_validate) {
... } else { ... }.

- Taking AccessExclusiveLock initially to avoid a lock upgrade hazard.

- Rejiggering things so that we apply map_partition_varattnos() to the
partConstraint in all relevant places.

Regarding the XXX, we currently require AccessExclusiveLock for the
addition of a CHECK constraint, so I think it's best to just do the
same thing here. We can optimize later, but it's probably not easy to
come up with something that is safe and correct in all cases.

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