[DRILL-7306] Disable "fast schema" batch for new scan framework

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.16.0
• Fix Version/s: 1.17.0
• Assignee: Paul Rogers
• Reporter: Paul Rogers
• Reviewer: Arina Ielchiieva
• Created: 24/Jun/19 02:12
• Updated: 08/Jul/19 10:43
• Resolved: 08/Jul/19 10:43

Description

The EVF framework is set up to return a "fast schema" empty batch with only schema as its first batch because, when the code was written, it seemed that's how we wanted operators to work. However, DRILL-7305 notes that many operators cannot handle empty batches.

Since the empty-batch bugs show that Drill does not, in fact, provide a "fast schema" batch, this ticket asks to disable the feature in the new scan framework. The feature is disabled with a config option; it can be re-enabled if ever it is needed.

Issue Links

• links to: GitHub Pull Request #1813