Orc table, missing map type columns


we added a Hive source but noticed that dremio does not load map type columns defined on orc tables.

The columns are defined as following:

Inital preview query does not report any errors.


When exactly are you running into the issue since you mentioned the preview works fine? Can you also share a query profile of the issue?

FYI - if it is an option, Dremio works best with Parquet

Hi, I guess I wasn’t clear enough. The preview does not work fine, since columns of type “map” are missing. It just doesn’t report any errors when fetching preview data, so we don’t know where to investigate.

Query profile attached.


ff5eb137-5572-46cb-b518-618c4ad60e38.zip (6.2 KB)

Which column is a map? Can you provide the output from Hive CLI of describe extended & describe formatted ?


outputs attached.


describe_table.zip (2.2 KB)

Thanks. Dremio currently doesn’t support Hive array, map, and interval data types. It is currently in our roadmap to support these types and to add better error handling/notification as well.

Hi @anthony , curious if you have any update on the support of Map types in Hive? We have a use case that could use that, right now we are skipping hive and going straight to parquet because of it.

Three years later and Map Types are still not supported in Dremio Cloud - at least such a column was missing when we connected a Glue Catalog table in Dremio. Is it still on the roadmap for implementation?

@radu.popa Should come up shortly, please check RN

@radu.popa See Introducing MAP Data Type in Dremio | Dremio