Re: [HACKERS] Insert result does not match record count

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Bruce Momjian <bruce(at)momjian(dot)us>
Cc: Vik Fearing <vik(dot)fearing(at)dalibo(dot)com>, Andres Freund <andres(at)2ndquadrant(dot)com>, Jeff Janes <jeff(dot)janes(at)gmail(dot)com>, Natalie Wenz <nataliewenz(at)ebureau(dot)com>, "pgsql-general(at)postgresql(dot)org" <pgsql-general(at)postgresql(dot)org>, PG Hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: [HACKERS] Insert result does not match record count
Date: 2014-01-31 21:38:21
Message-ID: 22395.1391204301@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general pgsql-hackers

Bruce Momjian <bruce(at)momjian(dot)us> writes:
> On Fri, Jan 31, 2014 at 06:34:27PM +0100, Vik Fearing wrote:
>> Unfortunately, I gave up on it as being over my head when I noticed I
>> was changing the protocol itself. I should have notified the list so
>> someone else could have taken over.

> OK, so that brings up a good question. Can we change the protocol for
> this without causing major breakage? Tom seems to indicate that it can
> be done for 9.4, but I thought protocol breakage was a major issue. Are
> we really changing the wire protocol here, or just the type of string we
> can pass back to the interface?

What I said about it upthread was "this is effectively a protocol change,
albeit a pretty minor one, so I can't see back-patching it".

The discussion in bug #7766 shows that some client-side code is likely to
need fixing, and that such fixing might actually be nontrivial for them.
So changing this in a minor release is clearly a bad idea. But I don't
have a problem with widening the counters in a major release where we
can document it as a potential compatibility issue.

I took a quick look and noted that CMDSTATUS_LEN and
COMPLETION_TAG_BUFSIZE are set to 64, and have been for quite a long time,
so command status string buffer sizes should not be a problem.

I think we probably just need to widen es_processed and touch related
code. Not sure what else Vik saw that needed doing.

regards, tom lane

In response to

Responses

Browse pgsql-general by date

  From Date Subject
Next Message Bruce Momjian 2014-01-31 21:56:00 Re: [HACKERS] Insert result does not match record count
Previous Message Raymond O'Donnell 2014-01-31 20:00:18 Re: Info

Browse pgsql-hackers by date

  From Date Subject
Next Message Bruce Momjian 2014-01-31 21:41:33 Re: mvcc catalo gsnapshots and TopTransactionContext
Previous Message Bruce Momjian 2014-01-31 21:37:41 Re: FOR UPDATE/SHARE incompatibility with GROUP BY, DISTINCT, HAVING and window functions