[DRILL-7143] Enforce column-level constraints when using a schema

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.16.0
• Fix Version/s: 1.16.0
• Labels: ready-to-commit
• Assignee: Paul Rogers
• Reporter: Paul Rogers
• Reviewer: Arina Ielchiieva
• Created: 30/Mar/19 21:41
• Updated: 08/Apr/19 10:49
• Resolved: 08/Apr/19 10:49

Description

The recently added schema framework enforces schema constraints at the table level. We now wish to add additional constraints at the column level.

• If a column is marked as "strict", then the reader will use the exact type and mode from the column schema, or fail if it is not possible to do so.
• If a column is marked as required, and provides a default value, then that value is used instead of 0 if a row is missing a value for that column.

This PR may also contain other fixes the the base functional revealed through additional testing.

Issue Links

• Dependent: DRILL-6835 Schema Provision using File / Table Function
• links to: GitHub Pull Request #1726