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From Fabian Hueske <fhue...@gmail.com>
Subject Re: How can handles Exist ,not Exist query on flink
Date Tue, 07 Jul 2015 14:56:48 GMT
Hi,

if you decorrelate the subquery, you can execute EXIST or NOT EXIST with a
join or co group.

If you search for "subquery decorrelation" you will find a good amount of
information.
Note that subquery decorrelation is not possble in general. Queries with
subqueries that cannot be decorrelated cannot be executed efficiently by
Flink (and other parallel system struggle with that as well).

cheers, Fabian

2015-07-07 16:26 GMT+02:00 hagersaleh <loveallah1987@yahoo.com>:

> please help
>
>
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