Re: Writeable CTEs - Mailing list pgsql-hackers

From Robert Haas
Subject Re: Writeable CTEs
Date
Msg-id 603c8f071001051346q643aa537xa9253029e1f9a69b@mail.gmail.com
Whole thread Raw
In response to Re: Writeable CTEs  (Josh Berkus <josh@agliodbs.com>)
Responses Re: Writeable CTEs  (Josh Berkus <josh@agliodbs.com>)
List pgsql-hackers
On Tue, Jan 5, 2010 at 4:20 PM, Josh Berkus <josh@agliodbs.com> wrote:
> On 1/5/10 9:45 AM, Marko Tiikkaja wrote:
>> On 2010-01-05 19:21 +0200, Greg Stark wrote:
>>> with t as (delete from foo returning *)
>>> select * from t where x=?
>>>
>>> applications will almost certainly expect the number to match the
>>> actual number of rows returned and may well misbehave if they don't.
>>
>> I probably wasn't clear about the actual problem in the original post.
>> The problem only affects INSERT, UDPATE and DELETE where you are
>> actually counting affected rows (i.e. PQcmdTuples(), not PQntuples()) so
>> the this example would work as expected.
>
> I don't think there is an "as expected" for this situation; people won't
> know what to expect. So what do we think is resonable?  The current
> behavior, which reports the total count of rows expected, works for me.

I agree with Tom's statement upthread that we should only count the
rows affected by the top-level query.  Anything else seems extremely
counter-intuitive.

...Robert


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