[jira] [Updated] (DRILL-6313) ScanBatch.Mutator does not report new schema for empty first batch

["Pritesh Maker (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/DRILL-6313?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Pritesh Maker updated DRILL-6313:
---------------------------------
    Fix Version/s:     (was: 1.14.0)

> 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
>            Priority: Major
>
> 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)