Stefán Baxter created DRILL-4548: ------------------------------------ Summary: Drill can not select from multiple Avro files Key: DRILL-4548 URL: https://issues.apache.org/jira/browse/DRILL-4548 Project: Apache Drill Issue Type: Bug Components: Storage - Avro Affects Versions: 1.6.0, 1.7.0 Reporter: Stefán Baxter
Hi, I have reworked/refactored our Avro based logging system trying to make the whole Drill + Avro->Parquet experience a bit more agreeable. Long story short I'm getting this error when selecting form multiple Avro files even though these files share the EXCACT same schema: Error: UNSUPPORTED_OPERATION ERROR: Hash aggregate does not support schema changes Fragment 0:0 [Error Id: 00d49aa2-5564-497e-a330-e852d5889beb on swift:31010] (state=,code=0) We are using union types but only to allow for null values as seems to be supported by drill as per this comment in the Drill code: // currently supporting only nullable union (optional fields) like ["null", "some-type"]. This happens for a very simple group_by + count(*) query that only uses two fields in Avro and neither one of them uses a Union construct so and both of them contain string values in every case. I now think this has nothing to do with the union types since the query uses only simple string, unless there is a full schema validation done on the content of the files rather then the identical Avro schema embedded in both files. -- This message was sent by Atlassian JIRA (v6.3.4#6332)