[DRILL-7509] Incorrect TupleSchema is created for DICT column when querying Parquet files

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.16.0
• Fix Version/s: 1.18.0
• Labels: ready-to-commit
• Assignee: Bohdan Kazydub
• Reporter: Bohdan Kazydub
• Reviewer: Igor Guzenko
• Created: 02/Jan/20 12:17
• Updated: 05/Feb/20 09:23
• Resolved: 29/Jan/20 13:39

Description

When DICT column is queried from Parquet file, its TupleSchema contains nested element, e.g. `map`, itself contains `key` and `value` fields, rather than containing the `key` and `value` fields in the DICT's TupleSchema itself. The nested element, `map`, comes from the inner structure of Parquet's MAP (which corresponds to Drill's DICT) representation.

Issue Links

• is depended upon by: DRILL-7361 Add Map (Dict) support for schema provisioning using file
• links to: GitHub Pull Request #1954