importing mongo collections with array field - the virtual tables don't share the _id field

Hi all,

I have a mongo collection observations (with binary primary key as binary _id) with array field tag_names. When importing into elasticube, sisense has by default created a virtual table observations_tag_names table with columns (_id, observations_tag_names_dim1_idx, observations_tag_names). However, I'm unable to join these 2 tables in sisense - the 2 tables have no overlap in the _id column which I use that as a join field.

1. Can you help me understand how to address/fix this? How does one import mongo collections with array fields?
2. The binary _id field itself seems to have changed. Eg _id = Binary('KPWTHQvkS3iTOY1vdhgEYQ==', 3) in mongo is imported as text '[B@163f7218', which is neither an UUID nor hex representation of the binary. How do I convert binary to a specific text representation when importing?

Thanks

Arvind