N-Dimensional Join Errors

[CristonS]

Occasionally you may see one of these errors from the Join Multiple tool. It is a result of Cartesian joins.

A Cartesian join is when you join every row of one table to every row of another table. You can also get one by joining every row of a table to every row of itself. A Cartesian join is very CPU intensive.

For example, if you have four files and each file has the same ID in it twice, that means it will join 2*2*2*2 times on the ID (the field on which you're joining is the key referenced in the error; in this example, it's Field1, and the duplicated value is 12345). The same can be caused by multiple nulls in each file.

After your data prep and investigation, and when you know your data are correct, your choices on how to handle Cartesian joins include:

• Allow multidimensional joins: The multidimensional join will occur with no error or warning reported.

• Warn on multidimensional joins of more than 16 records: A warning will be reported in the Results window that a multidimensional join has occurred.

• Error on multidimensional joins of more than 16 records: An error will be reported in the Results window that a multidimensional join has occurred and downstream processing will stop.

[martinoreb]

how do you resolve the error?

[CristonS]

hi @martinoreb, the error should resolve by selecting a different join option: Allow All or Warn.  Make sure to check for nulls, because they will join to each other across all your files!

[GideonM]

Thanks @CristonS, resolved my issue, i had same.

[PiyushJain]

Hi CristonS,

I am also facing the similar issue:

( Below is the issue deatils)..Please advise.

How to resolve this issue and how to identify and handle NULL.

I am facing below error/warning in alteryx designer workflow.

Error:

" 128 records were generated by an N - Dimensional Join key ( Business Region: XYZ ,COUNTRY: ABC).

My expected output rows : 210 to 250 rows

But i am getting 2300 rows

I checked and found ,output rows contains few null records, i sucpect that because of NULL ,my multiple join tool getting to much records like 2300 rows. ( but not sure).

I Tried below 2 options 

1. Warn on multidimensional joins....

2. Error on multidimensional  joins....

But still getting same above error.

I also tried option " Allow All multidimensional..."

But result is not expected. 

My input to Multiple Join tool is not contain any NULL ,But output contains Null values.

I checked throughly, but not able to figure out from where these nulls are coming. 

Please advise how to resolve issue.

Regards 

Piyush J

[CristonS]

hi @PiyushJain the best way to get a fast response is to post to the Designer discussion forum. Your question will have greater visibility and a wider range of responses.