<header>Default database type</header> <center><tt>default_database_type</tt></center> <hr> This parameter specifies the default database type to use in <tt>postalias(1)</tt> and <tt>postmap(1)</tt> commands. On many UNIX systems the default type is either <tt>`dbm'</tt> or <tt>`hash'</tt>. The default is determined when the Postfix system is built. <hr>