To cover up the improper translation of lateral table left outer join (
CALCITE-2004), we have temporarily forbidden the predicates (except true literal) in Table API ( FLINK-7853) and SQL ( FLINK-7854). Once the issue has been fixed in Calcite, we should remove the restrictions. The tasks may include removing Table API/SQL condition check, removing validation tests, enabling integration tests, updating the documents, etc.
See this thread on Calcite dev list for more information.