All processes blocked by a process using DBC.DBQLRuleTbl

Database

All processes blocked by a process using DBC.DBQLRuleTbl

Team,

Last night, all of the processes on our Teradata server were blocked, and they were blocked by a process using DBC.DBQLRuleTbl.  What process locks this table, and how could it hang all of the other processes?  Our only option was to "reset" the system.  We couldn't even login to kill the blocking process.