Important Configuration Files

Certain configuration files and the parameters are used by Oracle to resolve SIDs, find and load databases, and initialize data, checkpoint, log, monitoring-related and other parameters. The TNSNAMES.ORA file identifies services available on the system. This file refers to all databases (remote/local) that users may be connect to from SQL*plus or the OEM console. This file typically resides in the ORACLE_HOME\NETWORK\ADMIN directory. A section of the following sort should be added to this file for every oracle instance. Port 1521 is the default port on which a listener waits for a request:

orcl.mydb =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS =
(PROTOCOL = TCP)
(Host = <IP address or host name > )
(Port = 1521)
)
)
(CONNECT_DATA = (SID = ORCL)
)
)

Local databases may be identified with the "localhost" host name or the IP address 127.0.0.1. The listener.ora is a text file that contains descriptions of services that other systems may connect to and related configuration items. It is used to configure database listeners that accept remote connection requests. This file typically resides in the ORACLE_HOME\NETWORK\ADMIN directory and may contain sections for the listener name, listener address, databases served by the listener, and configuration parameters.

# Name of listener and addresses
LISTENER =
( ADDRESS_LIST =
(ADDRESS =
(PROTOCOL=tcp)
(HOST=<IP address or host name>)
(PORT=1521)
)
(ADDRESS =
(PROTOCOL=ipc)
(KEY=700)
)
)
 
# List of services offered
SID_LIST_LISTENER=
(SID_LIST=
(SID_DESC=
(SID_NAME=sampledb)
(ORACLE_HOME=D:\oracle92\)
)
)
 
 
# Start of configuration parameters.
TRACE_LEVEL_LISTENER=OFF
TRACE_FILE_LISTENER = "listener"
LOG_FILE_LISTENER = "listener"
CONNECT_TIMEOUT_LISTENER = 10
STOP_LISTENER = YES
DBA_GROUP = dba

The sqlnet.ora file contains configuration parameters for the machine at large as a single node in the network. This file is used by the SQL Net Services Manager and contains configuration details like tracing options, default domains, encryption, etc. across databases on the machine. This file typically resides in the ORACLE_HOME\NETWORK\ADMIN directory. The TRACE_LEVEL_CLIENT variable in the following example is related to log entries.

TRACE_LEVEL_CLIENT = OFF
SQLNET.EXPIRE_TIME = 20
SQLNET.AUTHENTICATION_SERVICES= (NTS)
NAMES.DIRECTORY_PATH= (TNSNAMES)