Re: delta relations in AFTER triggers

Kevin Grittner <kgrittn@gmail.com>

From: Kevin Grittner <kgrittn@gmail.com>
To: Thomas Munro <thomas.munro@enterprisedb.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Robert Haas <robertmhaas@gmail.com>, Haribabu Kommi <kommi.haribabu@gmail.com>, Jim Nasby <Jim.Nasby@bluetreble.com>, Craig Ringer <craig@2ndquadrant.com>, Michael Paquier <michael.paquier@gmail.com>, David Fetter <david@fetter.org>, Kevin Grittner <kgrittn@ymail.com>, Amit Khandekar <amit.khandekar@enterprisedb.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2017-04-04T23:49:46Z
Lists: pgsql-hackers
On Mon, Apr 3, 2017 at 7:16 PM, Thomas Munro
<thomas.munro@enterprisedb.com> wrote:
> On Tue, Apr 4, 2017 at 3:41 AM, Kevin Grittner <kgrittn@gmail.com> wrote:
>> On Mon, Apr 3, 2017 at 8:59 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>> Thomas Munro <thomas.munro@enterprisedb.com> writes:
>>>> Or perhaps the code to inject trigger data transition tables into SPI
>>>> (a near identical code block these three patches) should be somewhere
>>>> common so that each PLs would only need to call a function.  If so,
>>>> where should that go?
>>>
>>> spi.c?
>>
>> Until now, trigger.c didn't know about SPI, and spi.c didn't know
>> about triggers.  The intersection was left to referencing code, like
>> PLs.  Is there any other common code among the PLs dealing with this
>> intersection?  If so, maybe a new triggerspi.c file (or
>> spitrigger.c?) would make sense.  Possibly it could make sense from
>> a code structure PoV even for a single function, but it seems kinda
>> iffy for just this function.  As far as I can see it comes down to
>> adding it to spi.c or creating a new file -- or just duplicating
>> these 30-some lines of code to every PL.
>
> Ok, how about SPI_register_trigger_data(TriggerData *)?  Or any name
> you prefer...  I didn't suggest something as specific as
> SPI_register_transition_tables because think it's plausible that
> someone might want to implement SQL standard REFERENCING OLD/NEW ROW
> AS and make that work in all PLs too one day, and this would be the
> place to do that.
>
> See attached, which add adds the call to all four built-in PLs.  Thoughts?

Worked on the docs some more and then pushed it.

Nice job cutting the number of *.[ch] lines by 30 while adding support for
the other three core PLs.  :-)

-- 
Kevin Grittner


Commits

  1. Don't permit transition tables with TRUNCATE triggers.

  2. Pass EXEC_FLAG_REWIND when initializing a tuplestore scan.

  3. Faster expression evaluation and targetlist projection.

  4. Remove obsoleted code relating to targetlist SRF evaluation.

  5. Implement syntax for transition tables in AFTER triggers.