Mongo connector for BI: Wrong primary key on new table generated from array field

Hi,

I’m using the Mongo Connector for BI version 2.14.3 (since this version still supports mongo 3)

As expected, the mapping stage generated new tables for the array fields. In some collections, these new tables have a composite Primary Key with the fields “_id” (the identifier of the original document) and the “_idx” field (new field created after flattening the array). This is correct and the join to the original table works as expected. However, in other collections with array fields, the generated Primary Key is only the field “_id” (leaving out the idx field). In these cases, the join to the original table never ends.

This behaviour was seen on the Connector for BI version 2.14.3 for Ubuntu 18

Could you please help me?