Paul Rogers created DRILL-6313: ---------------------------------- Summary: ScanBatch.Mutator does not report new schema for empty first batch Key: DRILL-6313 URL: https://issues.apache.org/jira/browse/DRILL-6313 Project: Apache Drill Issue Type: Bug Affects Versions: 1.13.0 Reporter: Paul Rogers Assignee: Paul Rogers Fix For: 1.14.0
Create a format plugin that honors an empty select list by returning no columns. This case occurs in a {{COUNT(\*)}} query. When run, the query fails with: {noformat} SYSTEM ERROR: IllegalStateException: next() returned OK without first returning OK_NEW_SCHEMA [#2, ScanBatch] {noformat} The reason is that the {{Mutator}} class uses a flag, {{schemaChanged}}, which defaults to {{schemaChanged}}. It is set to {{true}} only when a field is added. But, since the query requested no fields, no field is added. The fix is simple, just default {{schemaChanged}} to {{true}}. -- This message was sent by Atlassian JIRA (v7.6.3#76005)