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N-Dimensional Join Errors

Alteryx Community Team
Alteryx Community Team
Created

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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.

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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.

 

n-dimensional join2.jpg

 

Happy Alteryx-ing!

Comments
6 - Meteoroid

how do you resolve the error?

Alteryx Community Team
Alteryx Community Team

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!

 

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