Fabian Hueske created FLINK-9419: ------------------------------------ Summary: UNION should not be treated as retraction producing operator Key: FLINK-9419 URL: https://issues.apache.org/jira/browse/FLINK-9419 Project: Flink Issue Type: Bug Components: Table API & SQL Reporter: Fabian Hueske
The following query fails {code} SELECT user_id, count(msg), HOP_END(rowtime, INTERVAL '1' second, INTERVAL '1' minute) FROM (SELECT rowtime, user_id, action_name AS msg FROM event_client_action WHERE /* various clauses */ UNION SELECT rowtime, user_id, action_type AS msg FROM event_server_action WHERE /* various clauses */ ) GROUP BY HOP(rowtime, INTERVAL '1' second, INTERVAL '1' minute), user_id {code} with {quote}Retraction on windowed GroupBy aggregation is not supported yet. Note: Windowed GroupBy aggregation should not follow a non-windowed GroupBy aggregation.{quote} The problem is that the {{UNION}} operator is translated into a {{UNION ALL}} and a subsequent {{GROUP BY}} on all attributes without an aggregation function. Currently, all {{GROUP BY}} operators are treated as retraction-producing operators. However, this is only true for grouping operators with aggregation functions. If the operator groups on all attributes and has no aggregation functions, it does not produce retractions but only forwards them (similar to a filter operator). -- This message was sent by Atlassian JIRA (v7.6.3#76005)