Re: pl/python invalidate functions with composite arguments

On Thu, Feb 10, 2011 at 9:06 PM, Alex Hunsaker <badalex(at)gmail(dot)com> wrote:
> On Wed, Feb 9, 2011 at 02:09, Jan Urbański <wulczer(at)wulczer(dot)org> wrote:
>> On 27/01/11 22:42, Jan Urbański wrote:
>>> On 23/12/10 14:50, Jan Urbański wrote:
>>>> Here's a patch implementing properly invalidating functions that have
>>>> composite type arguments after the type changes, as mentioned in
>>>> http://archives.postgresql.org/pgsql-hackers/2010-12/msg01991.php. It's
>>>> an incremental patch on top of the plpython-refactor patch sent eariler.
>>>
>>> Updated to master.
>>
>> Again.
>
> Looks good, it works as described, the code is clean and well
> documented and it passes the added regression tests.
>
> I took the liberty of looking at the other pls to see how they handled
> this to find they don't cache them in the first place. For fun, I
> hacked plpython to not cache to see if there was any performance
> difference pre patch, post patch and in the non-cached cases. I
> couldn't find any probably due to:
> 1) my simple test case (select
> count(test_composite_table_input('(John, 100, "(10)")')) FROM
> generate_series(1, 1000000);)
> 2) things being cached
> 3) cache invalidation having to do most of the work that the non
> caching cache does. I think there is one or two more SearchSysCall's.
> 4) overhead from cassert
>
> It seems a bit heavy handed to invalidate and remake the entire
> plpython function whenever we hit this case. I think we could get away
> with setting ->is_rowtype = 2 in PLy_procedure_valid() instead. I
> suppose it should be fairly rare case anyway so... *shrug*.

This last comment might make me think that we're looking for a new
version of this patch, but the comment on the CommitFest application
says "looks good". So I'm not sure whether this should be marked
Waiting on Author or Ready for Committer, but the current status of
Needs Review looks wrong.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
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