Re: FETCH FIRST clause PERCENT option

On 1/30/19 7:07 AM, Surafel Temesgen wrote:
> 
> 
> On Mon, Jan 28, 2019 at 1:28 AM Tomas Vondra
> <tomas.vondra@2ndquadrant.com <mailto:tomas.vondra@2ndquadrant.com>> wrote:
> 
> 
> 
>     OK. Does that mean you agree the incremental approach is reasonable?
> 
> 
> there are no noticeable performance difference but i love previous
> approach more regarding cursor operation it fetch tuple forward and
> backward from tuplestore only but in incremental approach we have to 
> re execute outer node in every forward and backward fetching operation
> 

I'm not sure I understand - are you saying every time the user does a
FETCH, we have to run the outer plan from scratch? I don't see why would
that be necessary? And if it is, how come there's no noticeable
performance difference?

Can you share a patch implementing the incremental approach, and a query
demonstrating the issue?

regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
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