Re: Writeable CTEs patch - Mailing list pgsql-hackers

From Marko Tiikkaja
Subject Re: Writeable CTEs patch
Date
Msg-id 4B72C5DE.2000704@cs.helsinki.fi
Whole thread Raw
In response to Re: Writeable CTEs patch  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-hackers
On 2010-02-08 18:42 +0200, Robert Haas wrote:
> On Thu, Feb 4, 2010 at 11:57 AM, Marko Tiikkaja
> <marko.tiikkaja@cs.helsinki.fi> wrote:
>> On 2010-02-04 18:04 UTC+2, I wrote:
>>> While working on the docs, I noticed one problem with the patch itself:
>>> it doesn't handle multi-statement DO INSTEAD rules correctly.  I'm going
>>> to submit a fix for that later.
>>
>> Here's an updated patch.  Only changes from the previous patch are
>> fixing the above issue and a regression test for it.
>
> - It appears that we pull out all of the DML statements first and run
> them in order, but I'm not sure that's the right thing to do.
> Consider:
>
> WITH x AS (INSERT ...), y AS (SELECT ...), z AS (INSERT ...) SELECT ...
>
> I would assume we would do x, CCI, do y, do z, CCI, do main query, but
> I don't think that's what this implements.  The user might be
> surprised to find out that y sees the effects of z.

I've updated the patch according to what I said here:
http://archives.postgresql.org/pgsql-hackers/2010-02/msg00722.php

I haven't done any extensive testing, but it seems to work in the most
common cases.


Regards,
Marko Tiikkaja

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