Apache Flink - Non equi joins

[M Singh]

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

[Fabian Hueske-2]

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 <[hidden email]>:

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

[M Singh]

Thanks Fabian for your detailed response.

Mans

On Monday, November 27, 2017 1:47 AM, Fabian Hueske <[hidden email]> 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 <[hidden email]>:

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