Re: Foreign join pushdown vs EvalPlanQual - Mailing list pgsql-hackers

From Etsuro Fujita
Subject Re: Foreign join pushdown vs EvalPlanQual
Date
Msg-id 56446AFD.2050208@lab.ntt.co.jp
Whole thread Raw
In response to Re: Foreign join pushdown vs EvalPlanQual  (Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>)
List pgsql-hackers
Horiguchi-san,

On 2015/11/12 16:10, Kyotaro HORIGUCHI wrote:
>>> I really don't see why you're fighting on this point.  Making this a
>>> generic feature will require only a few extra lines of code for FDW
>>> authors.  If this were going to cause some great inconvenience for FDW
>>> authors, then I'd agree it isn't worth it.  But I see zero evidence
>>> that this is actually the case.

>> Really?  I think there would be not a little burden on an FDW author;
>> when postgres_fdw delegates to the subplan to the remote server, for
>> example, it would need to create a remote join query by looking at
>> tuples possibly fetched and stored in estate->es_epqTuple[], send the
>> query and receive the result during the callback routine.

> Do you mind that FDW cannot generate a plan so that make a tuple
> from eqpTules then apply fdw_quals from predefined executor
> nodes?

No.  Please see my previous email.  Sorry for my unfinished email.

Best regards,
Etsuro Fujita




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