I successfully changed my monetdb admin password by logging in as admin, then running this command: sql>alter user set unencrypted password 'new password' using old password 'monetdb'; operation successful (50.027ms) sql> Instructions here: https://www.monetdb.org/Documentation/SQLreference/Users Note this only changes the password for the db into which you are logged. From: users-list <users-list-bounces+lcj34=cornell.edu@monetdb.org<mailto:users-list-bounces+lcj34=cornell.edu@monetdb.org>> on behalf of Roman S <rashkur@gmail.com<mailto:rashkur@gmail.com>> Reply-To: Communication channel for MonetDB users <users-list@monetdb.org<mailto:users-list@monetdb.org>> Date: Tuesday, June 28, 2016 at 11:04 AM To: "users-list@monetdb.org<mailto:users-list@monetdb.org>" <users-list@monetdb.org<mailto:users-list@monetdb.org>> Subject: Resetting monetdb administrative password Hello, Can somebody tell me how to reset monetdb administrative password? I've tried to stop mserver5, start it manually, oldp:=clients.getPasswordHash("monetdb"); newp:=clients.backendsum("newpassword"); clients.changePassword(oldp, newp); Stoping it again and start in normal mode But it didn't help: mclient --database=mydb --user=monetdb password:<usingnewpass> InvalidCredentialsException:checkCredentials:invalid credentials for user 'monetdb'