Re: Parallel Seq Scan - Mailing list pgsql-hackers

From Amit Langote
Subject Re: Parallel Seq Scan
Date
Msg-id 54C08A1A.20109@lab.ntt.co.jp
Whole thread Raw
In response to Re: Parallel Seq Scan  (Amit Kapila <amit.kapila16@gmail.com>)
List pgsql-hackers
On 22-01-2015 PM 02:30, Amit Kapila wrote:
>> Perhaps you are aware or you've postponed working on it, but I see that
>> a plan executing in a worker does not know about instrumentation.
> 
> I have deferred it until other main parts are stabilised/reviewed.  Once
> that is done, we can take a call what is best we can do for instrumentation.
> Thom has reported the same as well upthread.
> 

Ah, I missed Thom's report.

>> Note the "Rows Removed by Filter". I guess the difference may be
>> because, all the rows filtered by workers were not accounted for. I'm
>> not quite sure, but since exec_worker_stmt goes the Portal way,
>> QueryDesc.instrument_options remains unset and hence no instrumentation
>> opportunities in a worker backend. One option may be to pass
>> instrument_options down to worker_stmt?
>>
> 
> I think there is more to it, master backend need to process that information
> as well.
> 

I see.

Thanks,
Amit




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