Knowledge of database queries Knowledge of database theory Knowledge of database design Knowledge about the RDBMS itself, e.g. Microsoft SQL Server or MySQL Knowledge of structured query language (SQL), e.g. SQL/PSM or Transact-SQL General understanding of distributed computing architectures, e.g. Client–server model General understanding of operating system, e.g. Windows or Linux General understanding of storage technologies and networking General understanding of routine maintenance, recovery, and handling failover of a database