C *** ERROR => Connect to database failed, rc = -10709 (Connection failed (RTE:Database name is missing))

When you get the following error in MAXDB:

C  *** ERROR => Connect to database failed, rc = -10709 (Connection
failed (RTE:Database name is missing))

Please logon as user SAPService<SID> and check the xuser list and see if the Dbname is wrong.

xuser -c SAPSERVICE<SID> -U DEFAULT -u SAP<SID>,PASSWORd -d <SID>
                                        -n <SERVER NAME> -S SAPR3 -t0 -I 0 set

check also SAP help files:

http://maxdb.sap.com/doc/7_6/43/d77b97058201b4e10000000a11466f/frameset.htm

-> Switching on/off Automatic Extension of the Data Area