+* max_processes_backend - Maximum number of concurrent database processes for background tasks. Default value is 5.
+* max_processes_frontend - Maximum number of concurrent database processes for foreground tasks. Default value is 20.
+* memcache (Boolean) - Use memcache. To use memcache the PECL extension "memcache" has to be installed and activated.
+* memcache_host - Hostname of the memcache daemon. Default is '127.0.0.1'.
+* memcache_port- Portnumberof the memcache daemon. Default is 11211.