Dear users, I'm currently struggling with concurrent access to MonetDB/SQL via JDBC. Version: MonetDB server v5.20.4 (64-bit), based on kernel v1.38.4 (64-bit oids). I might still have some concurrency issues with my own code, but somehow I frequently end up with the following error message: (while stress-testing by querying with 10 threads at the same time) class java.sql.SQLException: TypeException:user.s3_1[448]:'user.contains' undefined in: _1933:any := user.contains(_1929:str, _1931:str, _474:bit) TypeException:user.s3_1[449]:'bat.insert' undefined in: _1934:any := bat.insert(_1923:bat[:oid,:bit], _1928:oid, _1933:any) TypeException:user.s3_1[645]:'user.contains' undefined in: _1946:any := user.contains(_1942:str, _1944:str, _474:bit) TypeException:user.s3_1[646]:'bat.insert' undefined in: _1947:any := bat.insert(_1938:bat[:oid,:bit], _1941:oid, _1946:any) TypeException:user.s3_1[1042]:'user.contains' undefined in: _1959:any := user.contains(_1955:str, _1957:str, _474:bit) TypeException:user.s3_1[1043]:'bat.insert' undefined in: _1960:any := bat.insert(_1951:bat[:oid,:bit], _1954:oid, _1959:any) TypeException:user.s3_1[1226]:'user.contains' undefined in: _1974:any := user.contains(_1970:str, _1972:str, _474:bit) TypeException:user.s3_1[1227]:'bat.insert' undefined in: _1975:any := bat.insert(_1964:bat[:oid,:bit], _1969:oid, _1974:any) SQLException:SQLengine:Program contains errors nl.cwi.monetdb.jdbc.MonetConnection$ResponseList.executeQuery(MonetConnection.java:2209) nl.cwi.monetdb.jdbc.MonetConnection$ResponseList.processQuery(MonetConnection.java:1968) nl.cwi.monetdb.jdbc.MonetStatement.internalExecute(MonetStatement.java:506) nl.cwi.monetdb.jdbc.MonetStatement.execute(MonetStatement.java:347) nl.cwi.monetdb.jdbc.MonetStatement.executeUpdate(MonetStatement.java:542) Does anyone else have experienced such error messages before, or does anyone have a clue to where to look? (like too many open connections, concurrent access of the same connection, querying a closed connection, or perhaps a bug inside monetdb)? Thanks, Wouter