Horton

Re: [HACKERS] [BUGS] BUG #14825: enum type: unsafe use?

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Thomas Munro <thomas.munro@enterprisedb.com>
Cc: Andres Freund <andres@anarazel.de>, Andrew Dunstan <andrew.dunstan@2ndquadrant.com>, Tom Lane <tgl@sss.pgh.pa.us>, Stephen Frost <sfrost@snowman.net>, Bruce Momjian <bruce@momjian.us>, "David E. Wheeler" <david@justatheory.com>, Christophe Pettus <christophe.pettus@pgexperts.com>, Postgres-Bugs <pgsql-bugs@postgresql.org>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2018-01-12T03:19:02Z
Lists: pgsql-bugs, pgsql-hackers 
On Thu, Jan 11, 2018 at 6:01 PM, Thomas Munro
<thomas.munro@enterprisedb.com> wrote:
> [ the data isn't session lifetime ]
>
> So I agree with Tom's suggestion:
>
> On Wed, Oct 4, 2017 at 2:29 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Perhaps serialize the contents into an array in DSM, then rebuild a hash
>> table from that in the worker.  Robert might have a better idea though.
>
> I'd happily volunteer to write or review a patch to do that.  Is there
> a rebase of the stuff that got reverted, to build on?

Those seem like reasons not to use Session, but not necessarily
reasons not to have the leader directly build the dshash that the
workers access rather than building a separate hash table in every
worker.

Maybe having every worker build a separate hash table is a good idea
for some reason, but it's not clear to me that you've stated such a
reason.

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

Commits

  1. Revert to 9.6 treatment of ALTER TYPE enumtype ADD VALUE.

  2. Remove heuristic same-transaction test from check_safe_enum_use().

  3. Use a blacklist to distinguish original from add-on enum values.

  4. Add support for coordinating record typmods among parallel workers.