Re: How to create a cursor that is independent of transactions and doesn't calculated when created ?

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От boraldomaster
Тема Re: How to create a cursor that is independent of transactions and doesn't calculated when created ?
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Msg-id 1372954092423-5762592.post@n5.nabble.com
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Ответ на Re: How to create a cursor that is independent of transactions and doesn't calculated when created ?  (David Johnston <polobo@yahoo.com>)
Ответы Re: How to create a cursor that is independent of transactions and doesn't calculated when created ?  (David Johnston <polobo@yahoo.com>)
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David Johnston wrote
> Your original examples only create the cursor and do not actually use it.
> You should be comparing how long it takes both examples to fetch the first
> 10 pages of records to get a meaningful comparison.  It won't matter if
> the DECLARE only takes 3ms in the non-hold case if retrieving the first
> page of records take 2s.

Certainly -
*close all;
begin;
declare mycursor cursor for select * from z order by name;
fetch 10 from mycursor;
commit;
*
 - takes 3 ms all.
Each *fetch 10 from mycursor* takes 1-2 ms.
So this is perfectly optimized in transaction. And I wonder why isn't it
optimized for a whole session.



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