Re: Parameterized aggregate subquery (was: Pull up aggregate subquery)

2011/6/29 Yeb Havinga <yebhavinga(at)gmail(dot)com>:
>
> On 2011-06-17 09:54, Hitoshi Harada wrote:
>>
>> While reviewing the gist/box patch, I found some planner APIs that can
>> replace parts in my patch. Also, comments in includes wasn't updated
>> appropriately. Revised patch attached.
>
> Hello Hitoshi-san,

Hi Yeb,

> I read your latest patch implementing parameterizing subquery scans.

> 6) Before patching Postgres, I could execute the test with the size_l and
> size_m tables, after patching against current git HEAD (patch without
> errors), I get the following error when running the example query:
> ERROR:  plan should not reference subplan's variable
>
> I get the same error with the version from june 9 with current git HEAD.

It seems that something has changed since I developed the patch at
first. The last one and the one before are not so different with each
other, especially in terms of runtime but might not be tested enough.
I tried time-slip of the local git branch to around june 10, but the
same error occurs. The error message itself is not in parts changed
recently, so I guess some surrounding change would affect it.

> 7) Since both set_subquery_pathlist and best_inner_subqueryscan push down
> clauses, as well as add a path and subplan, could a generalized function be
> made to support both, to reduce duplicate code?

I tried it but decided as it is, for the future extensibility. The
subquery parameterizing will (can) be extended more complicatedly. I'm
not sure if we'd better gathering some small parts into one by
throwing future capability.

Other things are all good points. Thanks for elaborate review!
More than anything, I'm going to fix the 6) issue, at least to find the cause.

Regards,
--
Hitoshi Harada