WHERE clause with contradicting condition should return no rows --------------------------------------------------------------- Key: TEIID-2473 URL: https://issues.jboss.org/browse/TEIID-2473 Project: Teiid Issue Type: Feature Request Components: Query Engine Affects Versions: 8.1 Environment: JZOS mainframe Reporter: Jeff Hayes Assignee: Steven Hawkins Priority: Minor Using Eclipse datasource explorer with teiid connection using SHOWPLAN to demonstrate the problem. Enter: SELECT * FROM SECURITY.SYSINFO WHERE SYSID = 'DE29 AND SYSID <> 'DE29' USER COMMAND appears as: SELECT * FROM SECURITY.SYSINFO WHERE SYSID = 'DE29 Apparently conflicting "AND SYSID <> 'DE29'" is dropped and I get results from SYSID = 'DE29'. Enter: SELECT * FROM SECURITY.SYSINFO WHERE SYSID <> 'DE29' AND SYSID = 'DE29' USER COMMAND appears as: SELECT * FROM SECURITY.SYSINFO WHERE 1 = 0 And I get expected null result set. Admittedly irrational query but it should give empty result set however you order the WHERE clause conditions.