Horton

Re: Parallel execution and prepared statements

Robert Haas <robertmhaas@gmail.com>

View thread
From: Robert Haas <robertmhaas@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: Albe Laurenz <laurenz.albe@wien.gv.at>, Tobias Bussmann <t.bussmann@gmx.net>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2016-12-01T16:10:49Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Enable parallelism for prepared statements and extended query protocol.

On Thu, Dec 1, 2016 at 7:57 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
> On Wed, Nov 30, 2016 at 11:57 PM, Robert Haas <robertmhaas@gmail.com> wrote:
>> On Tue, Nov 29, 2016 at 6:24 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
>>>
>>> Robert, do you have any better ideas for this problem?
>>
>> Not really.  I think your prepared_stmt_parallel_query_v2.patch is
>> probably the best approach proposed so far, but I wonder why we need
>> to include DestCopyOut and DestTupleStore.  DestIntoRel and
>> DestTransientRel both write to an actual relation, which is a problem
>> for parallel mode, but I think the others don't.
>>
>
> I have tried to restrict all the non-readonly operation modes or modes
> where parallelism might not make sense like DestTupleStore.  If we
> want to just prohibit the cases where it can fail now, then I think
> prohibiting only DestIntoRel should be sufficient because that is a
> case where the user is allowed to do DDL for an already prepared read
> only statement like Create Table AS .. EXECUTE.

OK, then my vote is to do it that way for now.

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