You are viewing a plain text version of this content. The canonical link for it is here.

Posted to user@flink.apache.org by M Singh <ma...@yahoo.com> on 2017/11/25 17:08:40 UTC

Apache Flink - Non equi joins

Hi:
Is it possible to perform non-equi joins in Flink using the core or relational apis ?  Is there any documentation on what sort of joins are supported with their examples ?
Thanks
Mans

Re: Apache Flink - Non equi joins

Posted by M Singh <ma...@yahoo.com>.

Thanks Fabian for your detailed response.
Mans 

    On Monday, November 27, 2017 1:47 AM, Fabian Hueske <fh...@gmail.com> wrote:
 

 Hi Mans,

no, non-equi joins are not supported by the relational APIs because they can be prohibitively expensive to compute.There's one exception. Cross joins where one of the input tables is guaranteed to have a single row (because it is the result of a non-grouped aggregation) are supported in the batch Table API / SQL.
The documentation shows which types of joins are supported including examples (Table API [1], SQL [2]).
With the upcoming 1.4 release, windowed joins will be added for streaming queries.

Best, Fabian

[1] https://ci.apache.org/projects/flink/flink-docs-release-1.3/dev/table/tableApi.html#joins
[2] https://ci.apache.org/projects/flink/flink-docs-release-1.3/dev/table/sql.html#joins

2017-11-25 18:08 GMT+01:00 M Singh <ma...@yahoo.com>:

Hi:
Is it possible to perform non-equi joins in Flink using the core or relational apis ?  Is there any documentation on what sort of joins are supported with their examples ?
Thanks
Mans

Re: Apache Flink - Non equi joins

Posted by Fabian Hueske <fh...@gmail.com>.

Hi Mans,

no, non-equi joins are not supported by the relational APIs because they
can be prohibitively expensive to compute.
There's one exception. Cross joins where one of the input tables is
guaranteed to have a single row (because it is the result of a non-grouped
aggregation) are supported in the batch Table API / SQL.

The documentation shows which types of joins are supported including
examples (Table API [1], SQL [2]).
With the upcoming 1.4 release, windowed joins will be added for streaming
queries.

Best, Fabian

[1]
https://ci.apache.org/projects/flink/flink-docs-release-1.3/dev/table/tableApi.html#joins
[2]
https://ci.apache.org/projects/flink/flink-docs-release-1.3/dev/table/sql.html#joins

2017-11-25 18:08 GMT+01:00 M Singh <ma...@yahoo.com>:

> Hi:
>
> Is it possible to perform non-equi joins in Flink using the core or
> relational apis ?  Is there any documentation on what sort of joins are
> supported with their examples ?
>
> Thanks
>
> Mans
>