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