Q:Multiple databases using Single default listener ??

Question

I created a database on a host and have been using the default listener to connect to it - no entries in listener.ora/tnsnames.ora -
now I have another database created on the host (different service_names) , but am unable to connect to it using default listener
without making entry in tnsnames.ora .
Q - Why does this work for the first DB I created and not for the second ?
Edited by: user7480241 on May 28, 2009 8:16 PM
Additional details about the env
Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.2.0 - Production
With the Partitioning, OLAP and Data Mining options
SQL>
SQL> show parameter listener
NAME TYPE VALUE
local_listener string
remote_listener string
SQL> show parameter service_names
NAME TYPE VALUE
service_names string MAHARAJA
Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.2.0 - Production
With the Partitioning, OLAP and Data Mining options
SQL> show parameter listener
NAME TYPE VALUE
local_listener string
remote_listener string
SQL> show parameter service_names
NAME TYPE VALUE
service_names string MAHARAJ2
SQL>
-bash-3.00$ lsnrctl service
LSNRCTL for Solaris: Version 10.2.0.2.0 - Production on 29-MAY-2009 11:19:01
Copyright (c) 1991, 2005, Oracle. All rights reserved.
Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))
Services Summary...
Service "MAHARAJ2" has 1 instance(s).
Instance "MAHARAJ2", status READY, has 1 handler(s) for this service...
Handler(s):
"DEDICATED" established:0 refused:0 state:ready
LOCAL SERVER
Service "MAHARAJ2_XPT" has 1 instance(s).
Instance "MAHARAJ2", status READY, has 1 handler(s) for this service...
Handler(s):
"DEDICATED" established:0 refused:0 state:ready
LOCAL SERVER
Service "MAHARAJA" has 1 instance(s).
Instance "MAHARAJA", status READY, has 1 handler(s) for this service...
Handler(s):
"DEDICATED" established:0 refused:0 state:ready
LOCAL SERVER
Service "MAHARAJA_XPT" has 1 instance(s).
Instance "MAHARAJA", status READY, has 1 handler(s) for this service...
Handler(s):
"DEDICATED" established:0 refused:0 state:ready
LOCAL SERVER
Service "PLSExtProc" has 1 instance(s).
Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Handler(s):
"DEDICATED" established:0 refused:0
LOCAL SERVER
The command completed successfully
-bash-3.00$ tnsping MAHARAJA
TNS Ping Utility for Solaris: Version 10.2.0.2.0 - Production on 29-MAY-2009 11:20:01
Copyright (c) 1997, 2005, Oracle. All rights reserved.
Used parameter files:
/export/home/oracle/network/admin/sqlnet.ora
Used EZCONNECT adapter to resolve the alias
Attempting to contact (DESCRIPTION=(CONNECT_DATA=(SERVICE_NAME=MAHARAJA.))(ADDRESS=(PROTOCOL=TCP)(HOST=10.0.2.15)(PORT=1521)))
OK (30 msec)
-bash-3.00$ tnsping MAHARAJ2
TNS Ping Utility for Solaris: Version 10.2.0.2.0 - Production on 29-MAY-2009 11:20:10
Copyright (c) 1997, 2005, Oracle. All rights reserved.
Used parameter files:
/export/home/oracle/network/admin/sqlnet.ora
TNS-03505: Failed to resolve name
DB & Global Names
SQL> show parameter name
NAME TYPE VALUE
db_file_name_convert string
db_name string MAHARAJA
db_unique_name string MAHARAJA
global_names boolean FALSE
instance_name string MAHARAJA
lock_name_space string
log_file_name_convert string
service_names string MAHARAJA
SQL> show parameter name
NAME TYPE VALUE
db_file_name_convert string
db_name string MAHARAJ2
db_unique_name string MAHARAJ2
global_names boolean FALSE
instance_name string MAHARAJ2
lock_name_space string
log_file_name_convert string
service_names string MAHARAJ2
SQL>

Answer 1

Why does this work for the first DB I created and not for the second ?Because Oracle tries to make it easy for folks.
listener.ora is not required for V10.
tnsnames.ora changes are required so SQL*Net can identify the 2nd DB; so do the necessary as document at http://tahiti.oracle.com