[DRILL-6773] The renamed schema with aliases is not shown for queries on empty directories

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 1.14.0
• Fix Version/s: 1.15.0
• Component/s: Query Planning & Optimization
• Labels: ready-to-commit
• Assignee: Vitalii Diravka
• Reporter: Vitalii Diravka
• Reviewer: Arina Ielchiieva
• Created: 05/Oct/18 12:23
• Updated: 08/Oct/18 12:52
• Resolved: 08/Oct/18 12:52

Description

The query is not working:

0: jdbc:drill:zk=local> select WeekId, Product as ProductName from (select CAST(`dir0` as INT) AS WeekId, Product from dfs.`/tmp/empty_dir`);
+--+
| |
+--+
+--+
No rows selected (0.197 seconds)

but the following query without aliases works fine:

0: jdbc:drill:zk=local> select WeekId, Product from (select CAST(`dir0` as INT) AS WeekId, Product from dfs.`/tmp/empty_dir`);
+---------+----------+
| WeekId | Product |
+---------+----------+
+---------+----------+
No rows selected (0.276 seconds)

outProj for ProjectPrel was introduced in DRILL-5546. It marks top level Projects, which schema should be shown in result output.
ProjectAllowDupPrel should have the same.

Issue Links

• is caused by: DRILL-5546 Schema change problems caused by empty batch
• is related to: DRILL-6774 Wrong data types of empty batches schema for queries with aliases
• links to: GitHub Pull Request #1492