Re: Custom/Foreign-Join-APIs (Re: [v9.5] Custom Plan API)

KaiGai-san,

2015/04/14 14:04、Kouhei Kaigai <kaigai(at)ak(dot)jp(dot)nec(dot)com> のメール：
>
>> * Fix typos
>>
>> Please review the v11 patch, and mark it as “ready for committer” if it’s ok.
>>
> It's OK for me, and wants to be reviewed by other people to get it committed.
>

Thanks!

>> In addition to essential features, I tried to implement relation listing in EXPLAIN
>> output.
>>
>> Attached explain_forein_join.patch adds capability to show join combination of
>> a ForeignScan in EXPLAIN output as an additional item “Relations”. I thought
>> that using array to list relations is a good way too, but I chose one string value
>> because users would like to know order and type of joins too.
>>
> A bit different from my expectation... I expected to display name of the local
> foreign tables (and its alias), not remote one, because all the local join logic
> displays local foreign tables name.
> Is it easy to adjust isn't it? Probably, all you need to do is, putting a local
> relation name on the text buffer (at deparseSelectSql) instead of the deparsed
> remote relation.

Oops, that’s right. Attached is the revised version. I chose fully qualified name, schema.relname [alias] for the output. It would waste some cycles during planning if that is not for EXPLAIN, but it seems difficult to get a list of name of relations in ExplainForeignScan() phase, because planning information has gone away at that time.

--
Shigeru HANADA
shigeru(dot)hanada(at)gmail(dot)com