Re: [PATCH] Return command tag 'REPLACE X' for CREATE OR REPLACE statements.

On Fri, Jan 14, 2011 at 1:35 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>> If we're going to reject this patch on backwards-compatibility
>> grounds, we need to make an argument that the backward-compatibility
>> hazards are a real concern.  So, again, has anyone complained about
>> the changes we made in this area in 9.0?
>
> That 9.0 change was far less invasive than this: it only added a count
> field to SELECT and CTAS result tags.  Quite aside from the fact that
> the tag name stayed the same, in the SELECT case it's unlikely anyone
> would have checked the tag at all rather than just testing for
> PQresultStatus() == PGRES_TUPLES_OK.  So it was basically only changing
> the result for *one* command type.  I don't think it's a good basis for
> arguing that this patch won't cause problems.

Yeah, but that one command tag was SELECT. That's a pretty commonly
used command. Most production environments probably use all of the
commands affected by this patch together an order of magnitude less
often than they use SELECT.

Again, on what basis are we arguing that people are going to be
looking at the command tag of a command that always returns the same
tag? That seems pretty darn unlikely to me.

--
Robert Haas
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