Local Naming Parameters in the tnsnames.ora File

6 Local Naming Parameters in the tnsnames.ora File

Learn about the Oracle Net service names local naming parameters that you specify in the tnsnames.ora configuration file.

Overview of Local Naming Parameters
The tnsnames.ora file is a configuration file that contains network service names that are mapped to connect descriptors for the Local Naming method.
General Syntax of tnsnames.ora
In this example, you can see the general tnsnames.ora file syntax.
Using Multiple Descriptions in tnsnames.ora Files
In this example, you can see two connect descriptors with multiple addresses.
Multiple Address Lists in tnsnames.ora Files
The tnsnames.ora file supports connect descriptors with multiple lists of addresses, each with its own characteristics. Learn how to configure multiple address lists in tnsnames.ora files.
Connect-Time Failover and Client Load Balancing with Oracle Connection Managers
When tnsnames.ora connect descriptors have at least two protocol addresses for Oracle Connection Manager, you can also include parameters for connect-time failover and load balancing in the file.
Connect Descriptor Descriptions
Specify connect descriptors using the DESCRIPTION parameter. Identify multiple connect descriptors with the DESCRIPTION_LIST parameter.
Protocol Addresses
The protocol address section of a tnsnames.ora file specifies listener protocol addresses.
Optional Parameters for Address Lists
For multiple addresses, you can use the optional parameters to configure address lists.
Connection Data Section
Learn how to configure network connections with protocol addresses.
Security Section
The security section of the tnsnames.ora file specifies these security-related parameters for use with Oracle security features.
Timeout Parameters
The timeout section of the tnsnames.ora file provides the ability to specify timeout and retry configuration through the TNS connect string.
Compression Parameters
The compression section of the tnsnames.ora file provides the ability to enable compression and specify compression levels. These parameters can be set at the DESCRIPTION level of a connect string.

6.1 Overview of Local Naming Parameters

The tnsnames.ora file is a configuration file that contains network service names that are mapped to connect descriptors for the Local Naming method.

A net service name is an alias that is mapped to a database network address that is contained in a connect descriptor. A connect descriptor contains the location of the listener that is accessed through a protocol address and the service name of the database to which to connect. Clients and database servers that are clients of other database servers use the net service name when connecting with applications.

Typically, tools such as Oracle Database Configuration Assistant (DBCA) and Oracle Net Configuration Assistant (NETCA) create the tnsnames.ora file in the ORACLE_HOME/network/admin directory for Oracle Database installations, the GRID_HOME/network/admin directory for Oracle Grid Infrastructure installations, or the corresponding ORACLE_BASE_HOME/network/admin directory for a read-only Oracle home. Note that if you have installed multiple databases, then the file is created in the Oracle home or Grid home where DBCA or NETCA is run (or the Oracle base home for read-only instances).

The order for checking the tnsnames.ora file is:

The directory specified by the TNS_ADMIN environment variable
If the TNS_ADMIN environment variable is not set or the file is not found in the TNS_ADMIN directory:
- On Linux and UNIX: The ORACLE_HOME/network/admin directory (or its ORACLE_BASE_HOME/network/admin directory for a read-only Oracle home)
- On Windows: The ORACLE_HOME\network\admin directory (or its ORACLE_BASE_HOME\network\admin directory for a read-only Oracle home)
For a read-only Oracle home, if the file is not found in the Oracle base home:
- On Linux and UNIX: The ORACLE_HOME/network/admin directory
- On Windows: The ORACLE_HOME\network\admin directory

Note:

On Windows, the ORACLE_HOME location is determined by the ORACLE_HOME\bin\oracle.key file (which contains the name of the Windows Registry key where ORACLE_HOME is defined). Also, the TNS_ADMIN environment variable is used if it is set in the environment of the process. If you do not define the TNS_ADMIN environment variable in the environment or if the process is a service that does not have an environment, then Windows scans the registry for a TNS_ADMIN parameter.
With Oracle Instant Client, tnsnames.ora is located in the subdirectory of the Oracle Instant Client software. For example, in the /opt/oracle/instantclient_release_number/network/admin directory.

Related Topics

Oracle Database Net Services Administrator's Guide

Parent topic: Local Naming Parameters in the tnsnames.ora File

6.2 General Syntax of tnsnames.ora

In this example, you can see the general tnsnames.ora file syntax.

Here, DESCRIPTION contains the connect descriptor, ADDRESS contains the protocol address, and CONNECT_DATA contains database service identification information.

Example 6-1 Basic Format of tnsnames.ora File

net_service_name= 
 (DESCRIPTION= 
   (ADDRESS=(protocol_address_information))
   (CONNECT_DATA= 
     (SERVICE_NAME=service_name)
    )
  )

Parent topic: Local Naming Parameters in the tnsnames.ora File

6.3 Using Multiple Descriptions in tnsnames.ora Files

In this example, you can see two connect descriptors with multiple addresses.

A tnsnames.ora file can contain net service names with one or more connect descriptors. Each connect descriptor can contain one or more protocol addresses.

Use the tnsnames.ora parameter DESCRIPTION_LIST to define the list of connect descriptors.

Example 6-2 Net Service Name with Multiple Connect Descriptors in tnsnames.ora

net_service_name= 
 (DESCRIPTION_LIST=
  (DESCRIPTION=

   (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521))
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-svr)(PORT=1521))
   (CONNECT_DATA=
     (SERVICE_NAME=sales.us.example.com)))
  (DESCRIPTION=

   (ADDRESS=(PROTOCOL=tcp)(HOST=hr1-svr)(PORT=1521))
   (ADDRESS=(PROTOCOL=tcp)(HOST=hr2-svr)(PORT=1521))
   (CONNECT_DATA=
     (SERVICE_NAME=hr.us.example.com))))

Note:

Oracle Net Manager does not support multiple connect descriptors for a net service name if you use Oracle Connection Manager.

Parent topic: Local Naming Parameters in the tnsnames.ora File

6.4 Multiple Address Lists in tnsnames.ora Files

The tnsnames.ora file supports connect descriptors with multiple lists of addresses, each with its own characteristics. Learn how to configure multiple address lists in tnsnames.ora files.

The following example shows two address lists. The first address list features client load balancing and no connect-time failover. These setting apply only to protocol addresses that are within its ADDRESS_LIST. The second protocol address list does not enable client load loading balancing, but the list does enable connect-time failover. These settings affect only protocol addresses that are included in its ADDRESS_LIST. The client first tries the first or second protocol address at random, then it tries protocol addresses number three and four, in that order, and so on.

Example 6-3 Multiple Address Lists in tnsnames.ora Files

net_service_name= 
 (DESCRIPTION= 
  (ADDRESS_LIST= 
   (LOAD_BALANCE=on)
   (FAILOVER=off)
   (ADDRESS=(protocol_address_information))
   (ADDRESS=(protocol_address_information)))
  (ADDRESS_LIST= 
   (LOAD_BALANCE=off)
   (FAILOVER=on)
   (ADDRESS=(protocol_address_information))
   (ADDRESS=(protocol_address_information)))
  (CONNECT_DATA=
   (SERVICE_NAME=service_name)))

Note:

Oracle Net Manager supports only the creation of one protocol address list for a connect descriptor.
Oracle Net Services supports the IFILE parameter in the tnsnames.ora file, with up to three levels of nesting. You must add the parameter manually to the file. The following is an example of the syntax:
```
IFILE=/tmp/listener_em.ora
IFILE=/tmp/listener_cust1.ora
IFILE=/tmp/listener_cust2.ora 
```

Parent topic: Local Naming Parameters in the tnsnames.ora File

6.5 Connect-Time Failover and Client Load Balancing with Oracle Connection Managers

When tnsnames.ora connect descriptors have at least two protocol addresses for Oracle Connection Manager, you can also include parameters for connect-time failover and load balancing in the file.

Example 6-4 Multiple Oracle Connection Manager Addresses in tnsnames.ora

This example illustrates the failover of multiple Oracle Connection Manager protocol addresses.

sample1=
 (DESCRIPTION= 
   (SOURCE_ROUTE=yes) 
   (ADDRESS_LIST=
     (ADDRESS=(PROTOCOL=tcp)(HOST=host1)(PORT=1630))    # 1 
     (ADDRESS_LIST=  
       (FAILOVER=on) 
       (LOAD_BALANCE=off)                               #  2 
       (ADDRESS=(PROTOCOL=tcp)(HOST=host2a)(PORT=1630)) 
       (ADDRESS=(PROTOCOL=tcp)(HOST=host2b)(PORT=1630)))
     (ADDRESS=(PROTOCOL=tcp)(HOST=host3)(PORT=1521)))    #  3
   (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com)))

The previous syntax does the following:

The client connects to the protocol address of the first Oracle Connection Manager as indicated by:
(ADDRESS=(PROTOCOL=tcp)(HOST=host1)(PORT=1630))
Oracle Connection Manager connects to the first protocol address of another Oracle Connection Manager. If the first protocol address fails, then it tries to connect to the second protocol address. This sequence is specified with the following configuration:
```
(ADDRESS_LIST=  
  (FAILOVER=on) 
  (LOAD_BALANCE=off)
  (ADDRESS=(PROTOCOL=tcp)(HOST=host2a)(PORT=1630)) 
  (ADDRESS=(PROTOCOL=tcp)(HOST=host2b)(PORT=1630))) 
```
Oracle Connection Manager connects to the database service using the following protocol address:
(ADDRESS=(PROTOCOL=tcp)(HOST=host3)(PORT=1521))

Example 6-5 Client Load Balancing in tnsnames.ora

This example illustrates client load balancing among two Oracle Connection Managers and two protocol addresses:

sample2=
 (DESCRIPTION= 
   (LOAD_BALANCE=on)                                    # 1
   (FAILOVER=on)
   (ADDRESS_LIST= 
     (SOURCE_ROUTE=yes) 
     (ADDRESS=(PROTOCOL=tcp)(HOST=host1)(PORT=1630))    # 2
     (ADDRESS=(PROTOCOL=tcp)(HOST=host2)(PORT=1521)))
  (ADDRESS_LIST= 
     (SOURCE_ROUTE=yes) 
     (ADDRESS=(PROTOCOL=tcp)(HOST=host3)(port=1630)) 
     (ADDRESS=(PROTOCOL=tcp)(HOST=host4)(port=1521)))
   (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com)))  # 3

The previous syntax does the following:

The client selects an ADDRESS_LIST at random and fails over to the other address if the chosen ADDRESS_LIST fails. This is indicated if you set the LOAD_BALANCE and FAILOVER parameters to on.
When an ADDRESS_LIST is chosen, the client first connects to Oracle Connection Manager using the Oracle Connection Manager protocol address that uses port 1630 as is indicated for the ADDRESS_LIST.
Oracle Connection Manager then connects to the database service using the protocol address that is indicated for the ADDRESS_LIST.

Parent topic: Local Naming Parameters in the tnsnames.ora File

6.6 Connect Descriptor Descriptions

Specify connect descriptors using the DESCRIPTION parameter. Identify multiple connect descriptors with the DESCRIPTION_LIST parameter.

DESCRIPTION_LIST
The DESCRIPTION_LIST parameter of the tnsnames.ora file defines a list of connect descriptors for a particular net service name.
DESCRIPTION
Use the tnsnames.ora file DESCRIPTION parameter to specify connect descriptor containers.

Parent topic: Local Naming Parameters in the tnsnames.ora File

6.6.1 DESCRIPTION_LIST

The DESCRIPTION_LIST parameter of the tnsnames.ora file defines a list of connect descriptors for a particular net service name.

Purpose

To define a list of connect descriptors for a particular net service name.

Example 6-6 Example

net_service_name= 
(DESCRIPTION_LIST=
 (DESCRIPTION=
  (ADDRESS=...)
  (CONNECT_DATA=(SERVICE_NAME=sales.example.com)))
 (DESCRIPTION=

Parent topic: Connect Descriptor Descriptions

6.6.2 DESCRIPTION

Use the tnsnames.ora file DESCRIPTION parameter to specify connect descriptor containers.

Purpose

To specify a container for a connect descriptor.

Usage Notes

When using more than one DESCRIPTION parameter, place the parameters under the DESCRIPTION_LIST parameter.

Example 6-7 DESCRIPTION Parameter Example

net_service_name=
(DESCRIPTION=
  (ADDRESS=...)
  (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com)))

Parent topic: Connect Descriptor Descriptions

6.7 Protocol Addresses

The protocol address section of a tnsnames.ora file specifies listener protocol addresses.

If there is only one listener protocol address, then use the ADDRESS parameter. If there is more than one address, then use the ADDRESS_LIST parameter.

ADDRESS
The tnsnames.ora parameter ADDRESS specifies protocol addresses with the ADDRESS_LIST for multiple addresses or with the DESCRIPTION parameter for one listener.
HTTPS_PROXY
Learn to use the tnsnames.ora parameter HTTPS_PROXY to specify HTTP proxy host names to tunnel Transport Layer Security (TLS) client connections.
HTTPS_PROXY_PORT
Learn how to use the tnsnames.ora parameter HTTPS_PROXY_PORT to specify forward HTTP proxy host ports for tunneling Transport Layer Security (TLS) client connections.
ADDRESS_LIST
The ADDRESS_LIST networking parameter specifies the number of protocol addresses.

Parent topic: Local Naming Parameters in the tnsnames.ora File

6.7.1 ADDRESS

The tnsnames.ora parameter ADDRESS specifies protocol addresses with the ADDRESS_LIST for multiple addresses or with the DESCRIPTION parameter for one listener.

Purpose

To specify one listener protocol address.

Usage Notes

Put this parameter under either the ADDRESS_LIST parameter or the DESCRIPTION parameter.

ADDRESS Parameter Example

net_service_name=
(DESCRIPTION= 
 (ADDRESS=(PROTOCOL=tcp)(HOST=sales-svr)(PORT=1521))
 (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com))

Parent topic: Protocol Addresses

6.7.2 HTTPS_PROXY

Learn to use the tnsnames.ora parameter HTTPS_PROXY to specify HTTP proxy host names to tunnel Transport Layer Security (TLS) client connections.

Purpose

To specify HTTP proxy host names for tunneling your TLS client connections.

Usage Notes

Your clients can tunnel secure connections over HTTP proxy using the HTTP CONNECT method. This helps access the public cloud database service because it eliminates the need to open an outbound port on a client-side firewall. This parameter is applicable only to the connect descriptors where PROTOCOL=TCPS. This is similar to the web browser setting for intranet users who want to connect to internet hosts. You can increase the forward web proxy read timeout for requests to a higher value depending on client queries. Otherwise, the forward web proxy closes the connection assuming that no requests are made from the client.

A successful connection depends on your specific proxy configurations. The performance of your data transfers depend on the proxy capacity. Oracle recommends against using this feature in production environments where performance is critical.

Configuring tnsnames.ora for an HTTP proxy may not be secure enough, depending your organization’s network configuration and security policies. For example, some networks require a user name and password for the HTTP proxy.

Oracle Client versions earlier than 18c does not support connections through HTTP proxy.

Contact your network administrator to open outbound connections to hosts that are in the oraclecloud.com domain by using the relevant port, without going through an HTTP proxy. For example, port 1522.

Default

None

Values

An HTTP proxy host name that can make an outbound connection to internet hosts.

Example

HTTPS_PROXY=www-proxy.example.com

Parent topic: Protocol Addresses

6.7.3 HTTPS_PROXY_PORT

Learn how to use the tnsnames.ora parameter HTTPS_PROXY_PORT to specify forward HTTP proxy host ports for tunneling Transport Layer Security (TLS) client connections.

Purpose

To specify forward HTTP proxy host port for tunneling TLS client connections.

Usage Notes

It forwards the HTTP proxy host port that receives the HTTP CONNECT method. Use this parameter with HTTPS_PROXY_PORT. The value for the HTTPS_PROXY_PORT parameter takes effect only when you set SQLNET.USE_HTTPS_PROXY=1 set in your sqlnet.ora file.

Default

none

Values

port number

Example

HTTPS_PROXY_PORT=80

Parent topic: Protocol Addresses

6.7.4 ADDRESS_LIST

The ADDRESS_LIST networking parameter specifies the number of protocol addresses.

Purpose

To define a list of protocol addresses.

Usage Notes

If there is only one listener protocol address, then ADDRESS_LIST is not necessary.

Put this parameter either under the DESCRIPTION parameter or the DESCRIPTION_LIST parameter.

Example

net_service_name=
 (DESCRIPTION= 
  (ADDRESS_LIST=
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521))
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-svr)(PORT=1521)))
  (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com)))

Parent topic: Protocol Addresses

6.8 Optional Parameters for Address Lists

For multiple addresses, you can use the optional parameters to configure address lists.

ENABLE
Use the ENABLE parameter to enable the keepalive feature on the supported TCP transports.
EXPIRE_TIME
Use the EXPIRE_TIME parameter to specify how often, in minutes, to verify that the remote server connection is active.
FAILOVER
Use the FAILOVER parameter to enable or disable connect-time failover for multiple protocol addresses.
LOAD_BALANCE
Use the LOAD_BALANCE parameter to enable or disable client load balancing for multiple protocol addresses.
RECV_BUF_SIZE
Use the RECV_BUF_SIZE parameter to specify buffer space for session receive operations.
SDU
Use the SDU parameter to configure the session data unit (SDU) size.
SEND_BUF_SIZE
Use the SEND_BUF_SIZE parameter to specify buffer space for session send operations.
SOURCE_ROUTE
Use the SOURCE_ROUTE parameter to enable routing through multiple protocol addresses.
TYPE_OF_SERVICE
Use the TYPE_OF_SERVICE parameter to specify the type of service to use for an Oracle Rdb database.

Parent topic: Local Naming Parameters in the tnsnames.ora File

6.8.1 ENABLE

Use the ENABLE parameter to enable the keepalive feature on the supported TCP transports.

Purpose

To allow the caller to detect a terminated remote server; typically it takes 2 hours or more to notice.

Usage Notes

The keepalive feature on the supported TCP transports can be enabled for a net service client by putting (ENABLE=broken) under the DESCRIPTION parameter in the connect string. On the client side, the default for tcp_keepalive is off. Operating system TCP configurables, which vary by platform, define the actual keepalive timing details.

Values

broken

Example

net_service_name=
 (DESCRIPTION= 
  (ENABLE=broken)
  (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521))
  (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-svr)(PORT=1521)))
  (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com))

Although the preceding example has multiple addresses, the ADDRESS_LIST parameter was not used. This is because the ADDRESS_LIST parameter is not mandatory.

Parent topic: Optional Parameters for Address Lists

6.8.2 EXPIRE_TIME

Use the EXPIRE_TIME parameter to specify how often, in minutes, to verify that the remote server connection is active.

Purpose

To specify time intervals, in minutes, for how often to verify that the remote server connection is active.

Usage Notes

Oracle Net Services tunes the TCP keepalive parameters so that probes are sent after an idle activity.

Limitations on using the terminated connection detection feature are:

You cannot use it on bequeathed connections.
Though very small, a probe packet generates additional traffic that may degrade your network performance.
Depending on your operating system, the server may need to perform additional processing to distinguish the connection probing event from other events. This can also result in a degraded network performance.

Default

Minimum Value

Recommended Value

Example


net_service_name=
   (DESCRIPTION=
     (EXPIRE_TIME=10)
     (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521)))
     (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com))

Parent topic: Optional Parameters for Address Lists

6.8.3 FAILOVER

Use the FAILOVER parameter to enable or disable connect-time failover for multiple protocol addresses.

Purpose

To enable or disable connect-time failover for multiple protocol addresses.

Usage Notes

When you set the parameter to on, yes, or true, Oracle Net fails over at connect time to a different address if the first protocol address fails. When you set the parameter to off, no, or false, Oracle Net tries one protocol address.

Put this parameter under the DESCRIPTION_LIST parameter, the DESCRIPTION parameter, or the ADDRESS_LIST parameter.

Note:

Do not set the GLOBAL_DBNAME parameter in the SID_LIST_listener_name section of the listener.ora. A statically configured global database name disables connect-time failover.

Default

on for the DESCRIPTION_LIST, DESCRIPTION, and ADDRESS_LIST parameters

Values

yes | on | true
no | off | false

Example

net_service_name=
 (DESCRIPTION= 
  (FAILOVER=on)
  (ADDRESS_LIST=
    (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521))
    (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-svr)(PORT=1521)))
  (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com)))

Parent topic: Optional Parameters for Address Lists

6.8.4 LOAD_BALANCE

Use the LOAD_BALANCE parameter to enable or disable client load balancing for multiple protocol addresses.

Purpose

To enable or disable client load balancing for multiple protocol addresses.

Usage Notes

When you set the parameter to on, yes, or true, Oracle Net goes through the list of addresses in a random sequence, balancing the load on the various listener or Oracle Connection Manager protocol addresses. When you set the parameter to off, no, or false, Oracle Net tries the protocol addresses sequentially until one succeeds.

Put this parameter under the DESCRIPTION_LIST parameter, the DESCRIPTION parameter, or the ADDRESS_LIST parameter.

Default

on for DESCRIPTION_LIST

Values

yes | on | true
no | off | false

Example

net_service_name=
 (DESCRIPTION= 
  (LOAD_BALANCE=on)
  (ADDRESS_LIST=
    (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521))
    (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-svr)(PORT=1521)))
  (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com))

Parent topic: Optional Parameters for Address Lists

6.8.5 RECV_BUF_SIZE

Use the RECV_BUF_SIZE parameter to specify buffer space for session receive operations.

Purpose

To specify, in bytes, the buffer space for receive operations of sessions.

Usage Notes

This parameter is supported by the TCP/IP, TCP/IP with TLS, and SDP protocols.

Put this parameter under the DESCRIPTION parameter or at the end of the protocol address.

Setting this parameter in the connect descriptor for a client overrides the RECV_BUF_SIZE parameter at the client-side sqlnet.ora file.

Note:

Additional protocols might support this parameter on certain operating systems. Refer to the operating system-specific documentation for additional information about additional protocols.

Default

The default value for this parameter is specific to the operating system. The default for the Linux 2.6 operating system is 87380 bytes.

Example

net_service_name= 
 (DESCRIPTION= 
   (ADDRESS_LIST=
     (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-server)(PORT=1521)
        (RECV_BUF_SIZE=11784))
     (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-server)(PORT=1521)
        (RECV_BUF_SIZE=11784))
   (CONNECT_DATA=
     (SERVICE_NAME=sales.us.example.com)))
net_service_name= 
 (DESCRIPTION= 
   (RECV_BUF_SIZE=11784)
   (ADDRESS_LIST=
     (ADDRESS=(PROTOCOL=tcp)(HOST=hr1-server)(PORT=1521))
     (ADDRESS=(PROTOCOL=tcp)(HOST=hr2-server)(PORT=1521)))
   (CONNECT_DATA=
     (SERVICE_NAME=hr.us.example.com)))

Related Topics

Oracle Database Net Services Administrator's Guide

Parent topic: Optional Parameters for Address Lists

6.8.6 SDU

Use the SDU parameter to configure the session data unit (SDU) size.

Purpose

To instruct Oracle Net to optimize the transfer rate of data packets being sent across the network with a specified SDU size.

Usage Notes

Put this parameter under the DESCRIPTION parameter.

Setting this parameter in the connect descriptor for a client overrides the DEFAULT_SDU_SIZE parameter at client-side sqlnet.ora file.

Default

8192 bytes (8 KB)

Values

512 to 2097152 bytes

Example

net_service_name= 
 (DESCRIPTION=
  (SDU=8192)
   (ADDRESS_LIST=
     (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-server)(PORT=1521))
     (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-server)(PORT=1521)))
  (CONNECT_DATA=
    (SERVICE_NAME=sales.us.example.com))

Related Topics

Oracle Database Net Services Administrator's Guide

Parent topic: Optional Parameters for Address Lists

6.8.7 SEND_BUF_SIZE

Use the SEND_BUF_SIZE parameter to specify buffer space for session send operations.

Purpose

To specify, in bytes, the buffer space for send operations of sessions.

Usage Notes

This parameter is supported by the TCP/IP, TCP/IP with TLS, and SDP protocols.

Put this parameter under the DESCRIPTION parameter or at the end of the protocol address.

Setting this parameter in the connect descriptor for a client overrides the SEND_BUF_SIZE parameter at the client-side sqlnet.ora file.

Note:

Additional protocols might support this parameter on certain operating systems. Refer to the operating system-specific documentation for information about additional protocols.

Default

The default value for this parameter is operating system specific. The default for the Linux 2.6 operating system is 16 KB.

Example

net_service_name= 
 (DESCRIPTION= 
   (ADDRESS_LIST=
     (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-server)(PORT=1521)
        (SEND_BUF_SIZE=11784))
     (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-server)(PORT=1521)
        (SEND_BUF_SIZE=11784)))
   (CONNECT_DATA=
     (SERVICE_NAME=sales.us.example.com)))
net_service_name= 
 (DESCRIPTION= 
   (SEND_BUF_SIZE=11784)
   (ADDRESS_LIST=
     (ADDRESS=(PROTOCOL=tcp)(HOST=hr1-server)(PORT=1521)
     (ADDRESS=(PROTOCOL=tcp)(HOST=hr2-server)(PORT=1521)))
   (CONNECT_DATA=
     (SERVICE_NAME=hr.us.example.com)))

Related Topics

Oracle Database Net Services Administrator's Guide

Parent topic: Optional Parameters for Address Lists

6.8.8 SOURCE_ROUTE

Use the SOURCE_ROUTE parameter to enable routing through multiple protocol addresses.

Purpose

To enable routing through multiple protocol addresses.

Usage Notes

When you set this parameter to on or yes, Oracle Net uses each address in order until the destination is reached.

To use Oracle Connection Manager, an initial connection from the client to Oracle Connection Manager is required, and a second connection from Oracle Connection Manager to the listener is required.

Put this parameter under either the DESCRIPTION_LIST parameter, the DESCRIPTION parameter, or the ADDRESS_LIST parameter.

Default

off

Values

yes | on
no | off

Example

net_service_name=
 (DESCRIPTION= 
  (SOURCE_ROUTE=on)
  (ADDRESS=(PROTOCOL=tcp)(HOST=cman-pc)(PORT=1630))
  (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521))
  (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com))

Related Topics

Oracle Database Net Services Administrator's Guide

Parent topic: Optional Parameters for Address Lists

6.8.9 TYPE_OF_SERVICE

Use the TYPE_OF_SERVICE parameter to specify the type of service to use for an Oracle Rdb database.

Purpose

To specify the type of service to use for an Oracle Rdb database.

Usage Notes

This parameter should only be used if the application supports both an Oracle Rdb and Oracle database service, and you want the application to load balance between the two.

Put this parameter under the DESCRIPTION parameter.

Example

net_service_name=
 (DESCRIPTION_LIST=
  (DESCRIPTION=
   (ADDRESS=...)
   (CONNECT_DATA= 
    (SERVICE_NAME=generic)
    (RDB_DATABASE=[.mf]mf_personal.rdb)
    (GLOBAL_NAME=alpha5))
   (TYPE_OF_SERVICE=rdb_database))
  (DESCRIPTION=
   (ADDRESS=...)
   (CONNECT_DATA=
    (SERVICE_NAME=sales.us.example.com))
   (TYPE_OF_SERVICE=oracle11_database)))

Related Topics

Oracle Database Net Services Administrator's Guide

Parent topic: Optional Parameters for Address Lists

6.9 Connection Data Section

Learn how to configure network connections with protocol addresses.

A network object is identified by a protocol address. When a connection is made, the client and the receiver of the request (listener or Oracle Connection Manager) are configured with identical protocol addresses. The client uses this address to send the connection request to a particular network object location, and the recipient "listens" for requests on this address, and grants a connection based on its address information matching the client information.

COLOCATION_TAG
CONNECT_DATA
Use the CONNECT_DATA parameter to define the connection service.
CONNECTION_ID_PREFIX
Use this parameter to add application specific ID to connection identifier.
FAILOVER_MODE
GLOBAL_NAME
HS
INSTANCE_NAME
KERBEROS5_PRINCIPAL
Use the KERBEROS5_PRINCIPAL parameter to set the Kerberos principal name associated with the Kerberos credentials cache (CC) file.
POOL_CONNECTION_CLASS
Use this parameter to explicitly name the connection class for Database Resident Connection Pooling (DRCP) connections.
POOL_PURITY
Use this parameter to specify if an application needs a new session that is not tainted with any prior session state or to reuse a previous session.
RDB_DATABASE
SHARDING_KEY
Use the SHARDING_KEY parameter to route the database connection request to an appropriate shard.
SUPER_SHARDING_KEY
Use the SUPER_SHARDING_KEY parameter in the case of composite sharding to route the database request to a collection of shards (shardspace).
SERVER
SERVICE_NAME
TUNNEL_SERVICE_NAME
Set this parameter to identify the client CMAN.

Parent topic: Local Naming Parameters in the tnsnames.ora File

6.9.1 COLOCATION_TAG

Purpose

To direct the listener to route all connections with the same colocation_tag to the same database instance.

Usage Notes

Use this parameter with the CONNECT_DATA parameter.

The parameter value must be an alphanumeric string.

Example


net_service_name=
 (DESCRIPTION=
   (ADDRESS_LIST=
    (ADDRESS=...)
    (ADDRESS=...))
 (CONNECT_DATA=
    (SERVICE_NAME=sales.us.example.com)
    (COLOCATION_TAG=abc)))

Note:

Under certain conditions, such as, when maximum load of an instance is reached or when new instances are added or deleted for a service, the colocation of client connections that have the same colocation_tag to the same database instance may not be consistent.

Parent topic: Connection Data Section

6.9.2 CONNECT_DATA

Use the CONNECT_DATA parameter to define the connection service.

Purpose

To define the service to which you want to connect, such as SERVICE_NAME.

Usage Notes

Put this parameter under the DESCRIPTION parameter. CONNECT_DATA permits additional parameters as listed in Connection Data Section.

Example

net_service_name=
 (DESCRIPTION= 
  (ADDRESS_LIST=
    (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521))
    (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-svr)(PORT=1521)))
  (CONNECT_DATA=
    (SERVICE_NAME=sales.us.example.com)))

Parent topic: Connection Data Section

6.9.3 CONNECTION_ID_PREFIX

Use this parameter to add application specific ID to connection identifier.

Usage Notes

Put this parameter under the CONNECT_DATA parameter.

Example


net_service_name=
(DESCRIPTION= 
   (ADDRESS_LIST=
     (ADDRESS=...)
     (ADDRESS=...))
   (CONNECT_DATA=
     (SERVICE_NAME=sales.us.example.com)
     ((CONNECTION_ID_PREFIX=value)))

Note:

The CONNECTION_ID_PREFIX value is appended internally to a system generated connection ID value and sent as CONNECTION_ID in connect string. The CONNECTION_ID_PREFIX must be an 8-byte alphanumeric identifier limited to the following [a...z] [A...Z] [0...9] _ character set.

Related Topics

Permitted Listener and Net Service Name Character Set

Parent topic: Connection Data Section

6.9.4 FAILOVER_MODE

Purpose

To instruct Oracle Net to fail over to a different listener if the first listener fails during run time.

Usage Notes

Depending upon the configuration, the session or any SELECT statements which were in progress are automatically failed over.

This type of failover is called Transparent Application Failover (TAF) and should not be confused with the connect-time failover FAILOVER parameter.

Put this parameter under the CONNECT_DATA parameter.

Additional Parameters

FAILOVER_MODE supports the following parameters:

BACKUP: Specifies the failover node by its net service name. A separate net service name must be created for the failover node.
TYPE: Specifies the type of failover. Three types of Oracle Net failover functionality are available by default to Oracle Call Interface (OCI) applications:
- SESSION: Fails over the session. For example, if a user's connection is lost, then a new session is automatically created for the user on the backup. This type of failover does not attempt to recover selects.
- SELECT: Allows users with open cursors to continue fetching them after failure. However, this mode involves overhead on the client side in normal select operations.
- NONE: This is the default, in which no failover functionality is used. This can also be explicitly specified to prevent failover from happening.
METHOD: Specifies how fast failover is to occur from the primary node to the backup node:
- BASIC: Establishes connections at failover time. This option requires almost no work on the backup database server until failover time.
- PRECONNECT: Pre-establishes connections. This provides faster failover but requires that the backup instance be able to support all connections from every supported instance.
TRANSACTION: Allows the database to complete the current database transaction following a recoverable error. This parameter is used with the COMMIT_OUTCOME=TRUE parameter.
RETRIES: Specifies the number of times to attempt to connect after a failover. If DELAY is specified, then RETRIES defaults to five retry attempts.
DELAY: Specifies the amount of time in seconds to wait between connect attempts. If RETRIES is specified, then DELAY defaults to one second.

Note:

If a callback function is registered, then RETRIES and DELAY parameters are ignored.

Related Topics

Oracle Database Net Services Administrator's Guide

Parent topic: Connection Data Section

6.9.5 GLOBAL_NAME

Purpose

To identify the Oracle Rdb database.

Usage Notes

Put this parameter under the CONNECT_DATA parameter.

Example

net_service_name= 
 (DESCRIPTION= 
   (ADDRESS_LIST=
    (ADDRESS=...)
    (ADDRESS=...))
   (CONNECT_DATA=
    (SERVICE_NAME=generic)
    (RDB_DATABASE=[.mf]mf_personal.rdb)
    (GLOBAL_NAME=alpha5)))

Parent topic: Connection Data Section

6.9.6 HS

Purpose

To direct Oracle Net to connect to a non-Oracle system through Heterogeneous Services.

Usage Notes

Put this parameter under the CONNECT_DATA parameter.

Default

None

Values

ok

Example

net_service_name= 
 (DESCRIPTION=
   (ADDRESS_LIST=
     (ADDRESS=...)
     (ADDRESS=...))
   (CONNECT_DATA=
    (SID=sales6)
    )
(HS=ok))

Related Topics

Oracle Database Net Services Administrator's Guide

Parent topic: Connection Data Section

6.9.7 INSTANCE_NAME

Purpose

To identify the database instance to access.

Usage Notes

Set the value to the value specified by the INSTANCE_NAME parameter in the initialization parameter file.

Put this parameter under the CONNECT_DATA parameter.

Example

net_service_name= 
 (DESCRIPTION=
   (ADDRESS_LIST=
     (ADDRESS=...)
     (ADDRESS=...))
   (CONNECT_DATA=
     (SERVICE_NAME=sales.us.example.com)
     (INSTANCE_NAME=sales1)))

6.9.8 KERBEROS5_PRINCIPAL

Use the KERBEROS5_PRINCIPAL parameter to set the Kerberos principal name associated with the Kerberos credentials cache (CC) file.

Purpose

When you configure Kerberos authentication for an Oracle Database client, you can specify multiple Kerberos principals with a single Oracle Database client.

This is an optional parameter. When specified, it is used to verify if the principal name in the credential cache (specified using SQLNET.KERBEROS5_CC_NAME) matches the parameter value.

Usage Notes

Use this parameter with the CONNECT_DATA parameter in the tnsnames.ora file. Alternatively, you can specify KERBEROS5_CC_NAME in the connect string along with the optional KERBEROS5_PRINCIPAL parameter to connect as a different Kerberos principal.

Each Kerberos principal must have a valid credential cache. Oracle Database checks KERBEROS5_PRINCIPAL against the value that is retrieved from the credential cache. If the two values do not match, then the user is not authenticated.

Example

For a user krbuser1, who is externally authenticated using the Kerberos principal krbprinc1.example.com and the credential cache for this principal is located at /tmp/krbuser1/krb.cc, the connect string is:


net_service_name=
(DESCRIPTION=
      (ADDRESS=(PROTOCOL=tcp)(HOST=sales-svr)(PORT=1521))
      (CONNECT_DATA=(SERVICE_NAME=sales.example.com)) 
      (SECURITY=
          (KERBEROS5_CC_NAME=/tmp/krbuser1/krb.cc)
          (KERBEROS5_PRINCIPAL=krbprinc1@example.com)))

Note:

The connection fails if the principal in the /tmp/krbuser1/krb.cc file does not contain the krbprinc1@example.com value.

Similarly, for a user krbuser2, who is externally authenticated using the Kerberos principal krbprinc2.example.com and the credential cache for this principal is located at /tmp/krbuser2/krb.cc, the connect string is:


net_service_name=
(DESCRIPTION=
      (ADDRESS=(PROTOCOL=tcp)(HOST=sales-svr)(PORT=1521))
      (CONNECT_DATA=(SERVICE_NAME=sales.example.com)) 
      (SECURITY=
          (KERBEROS5_CC_NAME=/tmp/krbuser2/krb.cc)
          (KERBEROS5_PRINCIPAL=krbprinc2@example.com)))

Related Topics

Parent topic: Connection Data Section

6.9.9 POOL_CONNECTION_CLASS

Use this parameter to explicitly name the connection class for Database Resident Connection Pooling (DRCP) connections.

Usage Notes

Add this parameter in the connect string under CONNECT_DATA section of the connect identifier. This parameter takes precedence and overrides the properties programmatically set by the application using this connect string.

Example


ServerPool =
 (DESCRIPTION=
   (ADDRESS=(PROTOCOL=tcp) (HOST=sales-svr) (PORT=1521))
   (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com)(SERVER=POOLED)(POOL_CONNECTION_CLASS=value)))

Related Topics

POOL_PURITY

Parent topic: Connection Data Section

6.9.10 POOL_PURITY

Use this parameter to specify if an application needs a new session that is not tainted with any prior session state or to reuse a previous session.

Usage Notes

Starting with Oracle Database 21c, you can configure Database Resident Connection Pooling (DRCP) for specific pluggable databases (PDBs). Add this parameter in the connect string under CONNECT_DATA section of the connect identifier to set purity attributes to a DRCP connection request.

This parameter takes precedence and overrides the properties programmatically set by the application using this connect string.

Values

NEW/SELF

Example


ServerPool =
 (DESCRIPTION=
   (ADDRESS=(PROTOCOL=tcp) (HOST=sales-svr) (PORT=1521))
   (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com)(SERVER=POOLED)(POOL_PURITY=value)))

Related Topics

POOL_CONNECTION_CLASS

Parent topic: Connection Data Section

6.9.11 RDB_DATABASE

Purpose

To specify the file name of an Oracle Rdb database.

Usage Notes

Put this parameter under the CONNECT_DATA parameter.

Example

net_service_name= 
 (DESCRIPTION= 
   (ADDRESS_LIST=
     (ADDRESS=...)
     (ADDRESS=...))
   (CONNECT_DATA=
     (SERVICE_NAME=sales.us.example.com)
     (RDB_DATABASE= [.mf]mf_personal.rdb)))

Parent topic: Connection Data Section

6.9.12 SHARDING_KEY

Use the SHARDING_KEY parameter to route the database connection request to an appropriate shard.

Purpose

To specify the value of a sharding key. Based on the value specified during a database connection request, the request is directly routed to the appropriate shard.

Usage Notes

You specify this parameter under the CONNECT_DATA section of a connect string or tnsnames.ora file.

Use the SHARDING_KEY parameter to specify a sharding key in simplified text format. This parameter supports only ASCII character set and not special characters. The following data types are supported for a sharding key:

NUMBER
INTEGER
SMALLINT
RAW
NVARCHAR
NVARCHAR2
NCHAR
DATE
TIMESTAMP

Use the SHARDING_KEY_B64 parameter to specify the base64-encoded binary representation of a sharding key. This parameter supports these special characters: " quotation mark , comma ( ) close parenthesis + plus sign)

Values

The fields for base64-encoded values (*_B64) start with a header, which is a sequence of space-separated integer values:

(CONNECT_DATA=
  (SHARDING_KEY_B64=
    [version][type][key column 1 type identifier][key column 2 type identifier] ... ,[base64 string],[base64 string],[base64 string],...))...

In the above syntax:

Parts of the compound key are separated with a comma.
version specifies the version number of base64 representation. Currently, only version 1 is supported, and thus the supported version value is 1.

type specifies the character set string and its encoding information. The supported type values are:

Value	Character Set String	Encoding Scheme
`0`	String contains hash value.	Character values are encoded in `AL32UTF8` (for `VARCHAR`) and `AL16UTF16` (for `NVARCHAR`).
`1`	String does not contain hash value.
`2`	String does not contain hash value.	Character values are encoded in database encoding, which may be specific for each column.
`3`	String contains hash value.
`4`	String contains only hash value.

key column type identifier specifies the data types. The supported key column type identifier values are:

Value	Data Type
`1`	`VARCHAR`, `NVARCHAR`, `CHAR`, `NCHAR`
`2`	`NUMBER`
`6`	`NUMBER` with length in first byte
`12`	`DATE`
`23`	`RAW`
`180`	`TIMESTAMP`

The header is terminated by a comma and is followed by base64 string. base64 string is a comma-separated list of the base64-encoded value string. The hash value, if available, is the last value in the list.

Example 6-8

In the following sample connect string, the SHARDING_KEY parameter value is specified in simplified text format:

net_service_name=
 (DESCRIPTION= 
  (ADDRESS_LIST=
    (ADDRESS=(host=sales-east1)(port=1522))
    (ADDRESS=(host=sales-east2)(port=1522))
  )
  (CONNECT_DATA=
    (SERVICE_NAME=sales.us.example.com)
    (SHARDING_KEY=40598230)
  )
 )

Example 6-9

In the following sample connect string, the SHARDING_KEY_B64 parameter value is encoded to base64 binary representation:

net_service_name=
 (DESCRIPTION=
  (ADDRESS_LIST=
    (ADDRESS=(host=sales-east1)(port=1522))
    (ADDRESS=(host=sales-east2)(port=1522))
  )
  (CONNECT_DATA=
    (SERVICE_NAME=sales.us.example.com)
    (SHARDING_KEY_B64=1 1 2,VVM=,OTQwMDI=)
  )
 )

Related Topics

Parent topic: Connection Data Section

6.9.13 SUPER_SHARDING_KEY

Use the SUPER_SHARDING_KEY parameter in the case of composite sharding to route the database request to a collection of shards (shardspace).

Purpose

To specify a shardspace key for a collection of shards. A shardspace is set of shards that store data that corresponds to a range or list of key values. Based on the value specified during a database connection request, the request is directly routed to an appropriate shardspace.

Usage Notes

You specify this parameter under the CONNECT_DATA section of a connect string or tnsnames.ora file.

Use the SUPER_SHARDING_KEY parameter to specify a shardspace key for a collection of shards in simplified text format. This parameter supports only ASCII character set and not special characters. The supported data types for a super sharding key are the same as those for a sharding key.

Use the SUPER_SHARDING_KEY_B64 parameter to specify the base64-encoded binary representation of a shardspace key. This parameter supports special characters (such as " quotation mark , comma ( ) close parenthesis + plus sign).

Values

The fields for base64-encoded values (*_B64) start with a header, which is a sequence of space-separated integer values:

(CONNECT_DATA=(SUPER_SHARDING_KEY_B64=[version] [type] [integer literal] [integer literal] ... ,[base64 binary],[base64 binary],[base64 binary],...))...

For details on each of the base64-encoded header fields, see SHARDING_KEY.

Example 6-10

In the following sample connect string, the SHARDING_KEY and SUPER_SHARDING_KEY parameter values are specified in simplified text format:

net_service_name=
 (DESCRIPTION= 
  (ADDRESS_LIST=
    (ADDRESS=(host=sales-east1)(port=1522))
    (ADDRESS=(host=sales-east2)(port=1522))
  )
  (CONNECT_DATA=
    (SERVICE_NAME=sales.us.example.com)
    ((SHARDING_KEY=40598230)(SUPER_SHARDING_KEY=gold))
  )
 )

Example 6-11

In the following sample connect string, the SHARDING_KEY_B64 and SUPER_SHARDING_KEY_B64 parameter values are encoded to base64 binary representation:

net_service_name=
 (DESCRIPTION= 
  (ADDRESS_LIST=
    (ADDRESS=(host=sales-east1)(port=1522))
    (ADDRESS=(host=sales-east2)(port=1522))
  )
  (CONNECT_DATA=
    (SERVICE_NAME=sales.us.example.com)
    ((SHARDING_KEY_B64=1 1 2,VVM=,OTQwMDI=)(SUPER_SHARDING_KEY_B64=1 1,BBWEPGRBBDOEMGQW))
  )
 )

Related Topics

Parent topic: Connection Data Section

6.9.14 SERVER

Purpose

To direct the listener to connect the client to a specific type of service handler.

Usage Notes

Put this parameter under the CONNECT_DATA parameter.

Values

dedicated to specify whether client requests be served by dedicated server.
shared to specify whether client requests be served by a dispatcher or shared server.
pooled to get a connection from the connection pool if database resident connection pooling is enabled on the server.

Note:

Shared server must be configured in the database initialization file in order for the client to connect to the database with a shared server process.
The USE_DEDICATED_SERVER parameter in the sqlnet.ora file overrides this parameter.

Example

net_service_name= 
 (DESCRIPTION=
   (ADDRESS_LIST=
     (ADDRESS=...)
     (ADDRESS=...))
   (CONNECT_DATA=
    (SERVICE_NAME=sales.us.example.com)
    (SERVER=dedicated)))

Parent topic: Connection Data Section

6.9.15 SERVICE_NAME

Purpose

To identify the Oracle Database database service to access.

Usage Notes

Set the value to a value specified by the SERVICE_NAMES parameter in the initialization parameter file.

Put this parameter under the CONNECT_DATA parameter.

Example

net_service_name= 
 (DESCRIPTION=
   (ADDRESS_LIST=
     (ADDRESS=...)
     (ADDRESS=...))
   (CONNECT_DATA=
     (SERVICE_NAME=sales.us.example.com)))

Related Topics

Oracle Database Net Services Administrator's Guide

Parent topic: Connection Data Section

6.9.16 TUNNEL_SERVICE_NAME

Set this parameter to identify the client CMAN.

Purpose

The server CMAN listener will route the connection to a gateway that has a tunnel connection to the requested client ID.

Usage Notes

Put this parameter under the CONNECT_DATA parameter.

Example


net_service_name=
(DESCRIPTION=
   (ADDRESS_LIST=
     (ADDRESS=...)
     (ADDRESS=...))
   (CONNECT_DATA=
     (SERVICE_NAME=sales.us.example.com)
     (TUNNEL_SERVICE_NAME=south)))

Related Topics

Oracle Database Net Services Administrator's Guide

Parent topic: Connection Data Section

6.10 Security Section

The security section of the tnsnames.ora file specifies these security-related parameters for use with Oracle security features.

AUTHENTICATION_SERVICE
Use the tnsnames.ora parameter AUTHENTICATION_SERVICE to enable an authentication service.
IGNORE_ANO_ENCRYPTION_FOR_TCPS
The IGNORE_ANO_ENCRYPTION_FOR_TCPS parameter specifies if the SQLNET.ENCRYPTION_CLIENT parameter should be ignored for this specific TNS alias.
KERBEROS5_CC_NAME
Use the tnsnames.ora parameter KERBEROS5_CC_NAME to specify the complete path name to the Kerberos credentials cache (CC) file.
SECURITY
Use the SECURITY parameter to change the security properties of a connection.
SSL_SERVER_CERT_DN
Use the SSL_SERVER_CERT_DN parameter to specify the distinguished name (DN) of the database server.
SSL_SERVER_DN_MATCH
Use the SSL_SERVER_DN_MATCH parameter to enforce server-side certificate validation through distinguished name (DN) matching.
SSL_VERSION
Use the SSL_VERSION parameter to define valid Transport Layer Security (TLS) versions to be used for connections.
WALLET_LOCATION
Use the WALLET_LOCATION parameter in the tnsnames.ora file to specify different locations where Oracle wallets are stored.

Parent topic: Local Naming Parameters in the tnsnames.ora File

6.10.1 AUTHENTICATION_SERVICE

Use the tnsnames.ora parameter AUTHENTICATION_SERVICE to enable an authentication service.

Purpose

To enable an authentication service. If you have installed authentication, then Oracle recommends that you set AUTHENTICATION_SERVICE to either NONE or to one of the listed authentication methods.

Usage Notes

Use this parameter in the SECURITY section of the tnsnames.ora file or directly as part of the connect string.

You can also set this value in the sqlnet.ora file. The AUTHENTICATION_SERVICE parameter is equivalent to the sqlnet.ora parameter SQLNET.AUTHENTICATION_SERVICES. The parameter value specified in the connect string takes precedence.

Note that the AUTHENTICATION_SERVICE parameter can take only a single authentication service, unlike the SQLNET.AUTHENTICATION_SERVICES parameter that can take multiple values.
When using the AUTHENTICATION_SERVICE=ALL, the server attempts to authenticate using each of the following methods:
1. Authentication based on a service external to the database, such as a service on the network layer, Kerberos, or RADIUS.
2. Authentication based on the operating system user's membership in an administrative operating system group. Group names are platform-specific. This authentication applies to administrative connections only.
3. Authentication performed by the database.
4. Authentication based on credentials stored in a directory server.
The server falls back to the authentication methods that appear further down on the list if attempts to use the authentication methods appearing higher on the list were unsuccessful.
When using local database password authentication (no external authentication), set AUTHENTICATION_SERVICE=NONE for better client performance.
Operating system authentication enables access to the database using any user name and any password when an administrative connection is attempted to the CDB root, such as using the AS SYSDBA clause when connecting using SQL*Plus.

An example of a connection to the CDB root is as follows.
```
sqlplus ignored_username/ignored_password AS SYSDBA
```
When the operating-system user who issued the preceding command is already a member of the appropriate administrative operating system group, then the connection is successful. This is because Oracle checks the group membership first, and thus the user name and password are ignored by the server.

Default

ALL

Note:

When installing Oracle Database with Database Configuration Assistant (DBCA), you can set this parameter to NTS in the sqlnet.ora file.

Values

Authentication methods that are available with Oracle Net Services:

NONE for no authentication methods, including Microsoft Windows native operating system authentication. When you set AUTHENTICATION_SERVICE to NONE, then the user can use a valid user name and password to access the database.
ALL for all authentication methods.
BEQ for native operating system authentication for operating systems other than Microsoft Windows.
KERBEROS5 for Kerberos authentication.
RADIUS for Remote Authentication Dial-In User Service (RADIUS) authentication.
TCPS for TLS authentication.
NTS for Microsoft Windows native operating system authentication. In this case, the user must authenticate to the database (CDB root) with OS credentials using Windows native authentication. No external password is needed. NTS checks the group membership for an OS user. For example, if an OS user is a member of the ORA_DBA group, then the user can log in to the database as SYSDBA.

Note:

With the AUTHENTICATION_SERVICE=NTS setting, if you try to connect through SQL*Plus using NTS authentication and specify an external password (for example, SQL*Plus SYSTEM/password), then the connection fails with an ORA-12638: credential retrieval failed error. For regular user name and password based authentication, set the value to NONE.

Example

net_service_name=
    (DESCRIPTION=
        (ADDRESS=(PROTOCOL=tcps)(HOST=sales-svr)(PORT=1521))
        (SECURITY=(AUTHENTICATION_SERVICE=KERBEROS5))
        (CONNECT_DATA=(SERVICE_NAME=sales.us.example.com))
    )

Related Topics

Parent topic: Security Section

6.10.2 IGNORE_ANO_ENCRYPTION_FOR_TCPS

The IGNORE_ANO_ENCRYPTION_FOR_TCPS parameter specifies if the SQLNET.ENCRYPTION_CLIENT parameter should be ignored for this specific TNS alias.

Purpose

To specify if the SQLNET.ENCRYPTION_CLIENT parameter should be ignored for this specific TNS alias.

Usage Notes

If your requirements are that SQLNET.ENCRYPTION_SERVER be set to required, then you can set the IGNORE_ANO_ENCRYPTION_FOR_TCPS parameter in both SQLNET.ENCRYPTION_CLIENT and SQLNET.ENCRYPTION_SERVER to TRUE. This forces the client to ignore the value that is set for the SQLNET.ENCRYPTION_CLIENT parameter for all outgoing TCPS connections.

Default

FALSE

Example 6-12 Example

test_ssl=
    (DESCRIPTION =
       (ADDRESS=(PROTOCOL=tcps)(HOST=)(PORT=1750))
       (CONNECT_DATA=(SID=^ORACLE_SID^))
       (SECURITY=(IGNORE_ANO_ENCRYPTION_FOR_TCPS=TRUE))
     )

Parent topic: Security Section

6.10.3 KERBEROS5_CC_NAME

Use the tnsnames.ora parameter KERBEROS5_CC_NAME to specify the complete path name to the Kerberos credentials cache (CC) file.

Purpose

To specify the complete path name to the Kerberos CC file.

Usage Notes

Use this parameter in the SECURITY section of the tnsnames.ora file or directly as part of the connect string.

You can also set this value in the sqlnet.ora file. The KERBEROS5_CC_NAME parameter is equivalent to the sqlnet.ora parameter SQLNET.KERBEROS5_CC_NAME. The parameter value specified in the connect string takes precedence.

Values and Examples

You can use the following formats to specify a value for KERBEROS5_CC_NAME:

If the Oracle database is using a directory cache:
- KERBEROS5_CC_NAME=complete_path_to_cc_file
  
  For example:
  
  KERBEROS5_CC_NAME=/tmp/kcache
  
  KERBEROS5_CC_NAME=D:\tmp\kcache
- KERBEROS5_CC_NAME=FILE:complete_path_to_cc_ file
  
  For example:
  
  KERBEROS5_CC_NAME=FILE:/tmp/kcache
If the Oracle database is using the native Windows cache:
- KERBEROS5_CC_NAME=OSMSFT://
- KERBEROS5_CC_NAME=MSLSA:
The OSMSFT and MSLSA options specify that the file is on Microsoft Windows and is running Microsoft Kerberos Key Distribution Center (KDC).

Note:

If you want to authenticate multiple Kerberos principals, then you can specify additional Kerberos principals either through the connect string directly or in the tnsnames.ora file.

Default

The default value is operating system-dependent, as follows:

On Linux and UNIX operating systems: /tmp/krb5cc_userid
On Microsoft Windows operating systems: c:\tmp\krbcache

Related Topics

Parent topic: Security Section

6.10.4 SECURITY

Use the SECURITY parameter to change the security properties of a connection.

Purpose

To change the security properties of a connection.

Usage Notes

Put this parameter under the DESCRIPTION parameter. SECURITY permits additional parameters as listed in Security Section.

Example

net_service_name=
 (DESCRIPTION= 
  (ADDRESS_LIST=
    (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521))
    (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-svr)(PORT=1521)))
  (CONNECT_DATA=
    (SERVICE_NAME=sales.us.example.com))
    (SECURITY=
      (SSL_SERVER_CERT_DN="cn=sales,cn=OracleContext,dc=us,dc=acme,dc=com")))

Parent topic: Security Section

6.10.5 SSL_SERVER_CERT_DN

Use the SSL_SERVER_CERT_DN parameter to specify the distinguished name (DN) of the database server.

Purpose

To specify the DN of the database server.

Usage Notes

The server DN must be known by the client ahead of time. Otherwise, the client cannot specify the server's DN in SSL_SERVER_CERT_DN. The client uses this information to obtain the list of DNs it expects for each of the servers, enforcing the database server DN to match its service name. This parameter must be set to the server DN (for example, SSL_SERVER_CERT_DN="finance, cn=OracleContext,c=us,o=example") to use full DN matching. For partial DN matching, do not include this parameter.

Use this parameter with the sqlnet.ora parameter SSL_SERVER_DN_MATCH to enable full DN matching.

Example

finance= 
 (DESCRIPTION=
   (ADDRESS_LIST=
     (ADDRESS=(PROTOCOL = tcps) (HOST = finance)
     (PORT = 1575)))
   (CONNECT_DATA=
     (SERVICE_NAME=finance.us.example.com))
   (SECURITY=
     (SSL_SERVER_CERT_DN="cn=finance,cn=OracleContext,c=us,o=example")))

Related Topics

Parent topic: Security Section

6.10.6 SSL_SERVER_DN_MATCH

Use the SSL_SERVER_DN_MATCH parameter to enforce server-side certificate validation through distinguished name (DN) matching.

Purpose

To enforce server-side certification validation through DN matching.

Usage Notes

If you enforce the DN matching, then in addition to verifying the server's certificate chain, the client performs another check through DN matching.

You can configure either partial DN matching or full DN matching. Partial DN matching occurs if the server's DN contains its host name. Full DN matching occurs against the server's complete DN. Not enforcing the match enables the server to potentially fake its identity.

In addition to the sqlnet.ora file, configure the tnsnames.ora parameter SSL_SERVER_CERT_DN to enable full DN matching.

Default

NO

Values

YES | ON | TRUE | 1:

To enforce partial or full DN matching. If the DN matches the service name, then the connection succeeds. If the DN does not match the service name, then the connection fails.
NO | OFF | FALSE | 0:

To not enforce DN matching. If the DN does not match the service name, then the connection is successful, but an error is logged to the sqlnet.log file.

Example

SSL_SERVER_DN_MATCH=YES

Related Topics

Parent topic: Security Section

6.10.7 SSL_VERSION

Use the SSL_VERSION parameter to define valid Transport Layer Security (TLS) versions to be used for connections.

Purpose

To define the version of TLS that must run on the systems with which the database server communicates. By default, the database server and client negotiate the strongest security protocol. Oracle does not recommend modifying this parameter, unless your security requirements mandate the usage of certain protocol versions.

Usage Notes

Clients, listeners, and database servers must use compatible versions. Modify this parameter only when necessary to enforce the use of the more secure TLS protocol and not allow clients that only work with the older TLS protocols. If you need to specify TLS 1.0 or TLS 1.1, then also include TLS 1.2 to allow more secure connections. The current default uses TLS 1.2, which is the version required for multiple security compliance requirements.
Starting with Oracle Database 21c, Transport Layer Security protocol version 1.0 (TLS 1.0) and 1.1 (TLS 1.1) are deprecated.

In accordance with security best practices, Oracle has deprecated the use of TLS 1.0 and TLS 1.1. To meet your security requirements, Oracle strongly recommends that you use TLS 1.2 instead.
If you set SSL_VERSION to undetermined, then the most secure TLS protocol version is used. You can use the SSL_VERSION=undetermined setting in the connect string for a specific connection to override the SSL_VERSION value configured in the sqlnet.ora file.
If you do not set SSL_VERSION to any value, then all the supported TLS protocol versions are tried starting with the most secure version. This is typically the most common configuration, ensuring that the strongest protocol is chosen during TLS negotiation.

Default

undetermined

Values

undetermined | 1.0 | 1.1 | 1.2

The version numbers correspond to the TLS versions, such as TLSv1.0, TLSv1.1, and TLSv1.2.

Note:

The sqlnet.ora parameter ADD_SSLV3_TO_DEFAULT has no impact on this parameter.

Syntax and Examples

To specify a single TLS version:

SSL_VERSION=TLS_protocol_version

For example:

SSL_VERSION=1.2

To specify multiple TLS versions, use the or operator as follows:

SSL_VERSION=TLS_protocol_version1 or TLS_protocol_version2

For example:

SSL_VERSION=1.1 or 1.2

SSL_VERSION=1.0 or 1.1 or 1.2

Related Topics

Parent topic: Security Section

6.10.8 WALLET_LOCATION

Use the WALLET_LOCATION parameter in the tnsnames.ora file to specify different locations where Oracle wallets are stored.

Purpose

This parameter denotes a connection specific wallet. You can use this parameter when different connections need to use different wallets on the client side.

Usage Notes

You can use WALLET_LOCATION in both the sqlnet.ora file and tnsnames.ora file. Use of WALLET_LOCATION in tnsnames.ora overrides the WALLET_LOCATION in sqlnet.ora for the specific tnsnames.ora service.

WALLET_LOCATION enables a client connection to have distinct TLS connections that use certificates. This means that the clients will initiate multiple TLS connections using different TLS certificates, in the same client process.

Use this parameter if you have a single client that must rely on more than one TLS session. An example would be for a client that requires access to multiple pluggable databases (PDBs), each with its own identity (certificate). This feature enables you to configure the client to connect to the correct identity for each PDB. After the configuration is complete, multi-threaded clients are able to access more than one wallet with different certificates in simultaneous TLS sessions.

Examples


net_service_name=
 (DESCRIPTION=
   (ADDRESS_LIST=
     (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521))
     (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-svr)(PORT=1521)))
   (CONNECT_DATA=
     (SERVICE_NAME=sales.us.example.com))
      (SECURITY=(wallet_location=/home/oracle/wallets/databases)))


ssl_certs1 = 
    (DESCRIPTION = 
       (ADDRESS=(PROTOCOL=tcps)(HOST=shobeen.us.example.com) (PORT=1750))
       (CONNECT_DATA=(SID=sales_pdb)) 
       (SECURITY=(WALLET_LOCATION=/oracle/wallets/certificates/sales_cert))
     )
ssl_certs2 = 
    (DESCRIPTION = 
       (ADDRESS=(PROTOCOL=tcps)(HOST=shobeen.us.example.com) (PORT=1750))
       (CONNECT_DATA=(SID=marketing_pdb)) 
       (SECURITY=(WALLET_LOCATION=/oracle/wallets/certificates/marketing_cert))
     )

Related Topics

Parent topic: Security Section

6.11 Timeout Parameters

The timeout section of the tnsnames.ora file provides the ability to specify timeout and retry configuration through the TNS connect string.

The following parameters can be set at the DESCRIPTION level of a connect string:

CONNECT_TIMEOUT
Use the tnsnames.ora parameter CONNECT_TIMEOUT to specify the amount of time, in milliseconds, seconds, or minutes, in which clients must establish Oracle Net connections to database instances.
RETRY_COUNT
Use the tnsnames.ora parameter RETRY_COUNT to specify the number of times an ADDRESS list is traversed before terminating the connection attempt.
RETRY_DELAY
Use the tnsnames.ora parameter RETRY_DELAY to specify the delay between connection retries.
TRANSPORT_CONNECT_TIMEOUT
Use the tnsnames.ora parameter TRANSPORT_CONNECT_TIMEOUT to specify the transport connect timeout duration, in milliseconds, seconds, or minutes.
RECV_TIMEOUT
Use the tnsnames.ora parameter RECV_TIMEOUT to specify the duration of time that a database client or server should wait for data from a peer after establishing a connection.

Parent topic: Local Naming Parameters in the tnsnames.ora File

6.11.1 CONNECT_TIMEOUT

Use the tnsnames.ora parameter CONNECT_TIMEOUT to specify the amount of time, in milliseconds, seconds, or minutes, in which clients must establish Oracle Net connections to database instances.

Purpose

To specify the timeout duration in ms or msec (milliseconds), sec (seconds), or min (minutes) for a client to establish an Oracle Net connection to Oracle Database.

Usage Notes

Put this parameter under the DESCRIPTION parameter.
In case, no unit is mentioned, the default unit is sec.

It accepts different timeouts with or without space between the value and the unit. For example:
```
CONNECT_TIMEOUT=10 ms
```
or
```
CONNECT_TIMEOUT=10ms
```
The timeout interval specified by CONNECT_TIMEOUT is a superset of the TCP connect timeout interval. It includes the time to be connected to the database instance providing the requested service, not just the duration of the TCP connection.

The timeout interval is applicable to each ADDRESS in an ADDRESS_LIST, and each IP address to which a host name is mapped.
The CONNECT_TIMEOUT parameter is equivalent to the sqlnet.ora parameter SQLNET.OUTBOUND_CONNECT_TIMEOUT, and overrides it.

Examples

net_service_name=
 (DESCRIPTION= 
  (CONNECT_TIMEOUT=10 ms)(RETRY_COUNT=3)
  (ADDRESS_LIST=
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521))
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-svr)(PORT=1521)))
  (CONNECT_DATA=
   (SERVICE_NAME=sales.us.example.com)))

Related Topics

SQLNET.OUTBOUND_CONNECT_TIMEOUT

Parent topic: Timeout Parameters

6.11.2 RETRY_COUNT

Use the tnsnames.ora parameter RETRY_COUNT to specify the number of times an ADDRESS list is traversed before terminating the connection attempt.

Purpose

To specify the number of times an ADDRESS list is traversed before the connection attempt is terminated.

Usage Notes

Put this parameter under the DESCRIPTION parameter.

When a DESCRIPTION_LIST is specified, each DESCRIPTION is traversed multiple times based on the specified number of retries.

Example

net_service_name= 
(DESCRIPTION_LIST=
 (DESCRIPTION=
  (CONNECT_TIMEOUT=10)(RETRY_COUNT=3)
  (ADDRESS_LIST=
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales1a-svr)(PORT=1521))
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales1b-svr)(PORT=1521)))
  (CONNECT_DATA=(SERVICE_NAME=sales1.example.com)))
 (DESCRIPTION=
  (CONNECT_TIMEOUT=60)(RETRY_COUNT=1)
  (ADDRESS_LIST=
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales2a-svr)(PORT=1521))
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales2b-svr)(PORT=1521)))
  (CONNECT_DATA=(SERVICE_NAME=sales2.us.example.com))))

Parent topic: Timeout Parameters

6.11.3 RETRY_DELAY

Use the tnsnames.ora parameter RETRY_DELAY to specify the delay between connection retries.

Purpose

To specify the delay between subsequent retries for a connection in units of ms or msec (milliseconds), sec (seconds), or min (minutes). This parameter works in conjunction with the RETRY_COUNT parameter.

Usage Notes

Put this parameter under the DESCRIPTION parameter.

When a DESCRIPTION_LIST is specified, each DESCRIPTION is traversed multiple times based on the specified number of retries, and the specific delay for the description.
In case, no unit is mentioned, the default unit is sec.

You can configure it with or without space between the value and the unit. For example:
```
RETRY_DELAY=800 ms
```
or
```
RETRY_DELAY=800ms
```

Example

net_service_name=
(DESCRIPTION_LIST=
  (DESCRIPTION=
   (CONNECT_TIMEOUT=10)(RETRY_COUNT=3)(RETRY_DELAY=800ms)
   (ADDRESS_LIST=
    (ADDRESS=(PROTOCOL=tcp)(HOST=myhost1)(PORT=1521))
    (ADDRESS=(PROTOCOL=tcp)(HOST=myhost2)(PORT=1521)))
   (CONNECT_DATA=(SERVICE_NAME=example1.com)))
  (DESCRIPTION=
   (CONNECT_TIMEOUT=60)(RETRY_COUNT=1)(RETRY_DELAY=5sec)
   (ADDRESS_LIST=
    (ADDRESS=(PROTOCOL=tcp)(HOST=myhost3)(PORT=1521))
    (ADDRESS=(PROTOCOL=tcp)(HOST=myhost4)(PORT=1521)))
   (CONNECT_DATA=(SERVICE_NAME=example2.com))))

Related Topics

RETRY_COUNT

Parent topic: Timeout Parameters

6.11.4 TRANSPORT_CONNECT_TIMEOUT

Use the tnsnames.ora parameter TRANSPORT_CONNECT_TIMEOUT to specify the transport connect timeout duration, in milliseconds, seconds, or minutes.

Purpose

To specify the transport connect timeout duration in ms or msec (milliseconds), sec (seconds), or min (minutes) for a client to establish an Oracle Net connection to Oracle Database.

Usage Notes

This parameter is put under the DESCRIPTION parameter.
The default value is 60 sec. In case, no unit is mentioned, the default unit is sec.

It accepts different timeouts with or without space between the value and the unit.
```
TRANSPORT_CONNECT_TIMEOUT=10 ms
```
or
```
TRANSPORT_CONNECT_TIMEOUT=10ms
```
The timeout interval is applicable for each ADDRESS in an ADDRESS_LIST description, and each IP address that a host name is mapped. The TRANSPORT_CONNECT_TIMEOUT parameter is equivalent to the sqlnet.ora parameter TCP.CONNECT_TIMEOUT, and overrides it.

Example

net_service_name =
  (DESCRIPTION=
    (TRANSPORT_CONNECT_TIMEOUT=10 ms)
    (ADDRESS_LIST=
      (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521))
      (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-svr)(PORT=1521)))
    (CONNECT_DATA=
      (SERVICE_NAME=sales.us.example.com)))

Related Topics

TCP.CONNECT_TIMEOUT

Parent topic: Timeout Parameters

6.11.5 RECV_TIMEOUT

Use the tnsnames.ora parameter RECV_TIMEOUT to specify the duration of time that a database client or server should wait for data from a peer after establishing a connection.

Purpose

To specify the time duration in ms or msec (milliseconds), sec (seconds), min (minutes), or hr (hours) for a database client or server to wait for data from the peer after establishing a connection. The peer must send data within the time interval that you specify.

Usage Notes

This parameter is put under the DESCRIPTION parameter.
If you do not specify a unit of measurement, then the default unit is sec.

It accepts time duration with or without space between the value and the unit. For example:
```
RECV_TIMEOUT=10 ms
```
or
```
RECV_TIMEOUT=10ms
```
Setting this parameter for clients ensures that receive operations are not left in a wait state indefinitely or for a long period due to server host being down, server busy state, or network connectivity issues.

If a client does not receive response data in the time specified, then the client logs ORA-12535: TNS:operation timed out and ORA-12609: TNS: Receive timeout occurred messages to the sqlnet.log file.

Default Value

None

Minimum Value

1 ms

Allowed Range

Any number greater than the minimum value of 1 ms up to 4294967295 ms.

Examples

net_service_name=
 (DESCRIPTION= 
  (CONNECT_TIMEOUT=10ms)(RETRY_COUNT=3)(RECV_TIMEOUT=10ms)
  (ADDRESS_LIST=
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-svr)(PORT=1521))
   (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-svr)(PORT=1521)))
  (CONNECT_DATA=
   (SERVICE_NAME=sales.us.example.com)))

Related Topics

Oracle Database Net Services Administrator's Guide

Parent topic: Timeout Parameters

6.12 Compression Parameters

The compression section of the tnsnames.ora file provides the ability to enable compression and specify compression levels. These parameters can be set at the DESCRIPTION level of a connect string.

COMPRESSION
The tnsnames.ora file’s compression parameter enables or disables the data compression.
COMPRESSION_LEVELS
The COMPRESSION_LEVELS parameter of the tnsnames.ora file specifies the compression level.

Parent topic: Local Naming Parameters in the tnsnames.ora File

6.12.1 COMPRESSION

The tnsnames.ora file’s compression parameter enables or disables the data compression.

Purpose

To enable or disable data compression.

Usage Notes

Put this parameter under the DESCRIPTION parameter.

Setting this parameter in the connect descriptor for a client overrides the SQLNET.COMPRESSION parameter in the client-side sqlnet.ora file.

Default

off

Values

on to enable data compression.
off to disable data compression.

Example

net_service_name=
 (DESCRIPTION=
   (COMPRESSION=on)
      (ADDRESS_LIST=
         (ADDRESS= (PROTOCOL=tcp) (HOST=sales1-server) (PORT=1521))
         (ADDRESS= (PROTOCOL=tcp) (HOST=sales2-server) (PORT=1521)))
   (CONNECT_DATA=
       (SERVICE_NAME=sales.us.example.com)))

Related Topics

SQLNET.COMPRESSION

Parent topic: Compression Parameters

6.12.2 COMPRESSION_LEVELS

The COMPRESSION_LEVELS parameter of the tnsnames.ora file specifies the compression level.

Purpose

To specify the compression level.

Usage Notes

The compression levels are used at the time of negotiation to verify which levels are used at both ends, and select one level. Put this parameter under the DESCRIPTION parameter.

This parameter is used with the COMPRESSION parameter. Setting this parameter in the connect descriptor for a client overrides the SQLNET.COMPRESSION_LEVELS parameter in the client-side sqlnet.ora file.

Default

low

Values

low for low CPU usage and a low compression ratio.
high for high CPU usage and a high compression ratio.

Example

net_service_name=
 (DESCRIPTION=
  (COMPRESSION=on)
  (COMPRESSION_LEVELS=(LEVEL=low)(LEVEL=high))
   (ADDRESS_LIST=
     (ADDRESS=(PROTOCOL=tcp)(HOST=sales1-server)(PORT=1521))
     (ADDRESS=(PROTOCOL=tcp)(HOST=sales2-server)(PORT=1521)))
  (CONNECT_DATA=
    (SERVICE_NAME=sales.us.example.com)))

Related Topics

SQLNET.COMPRESSION_LEVELS

Parent topic: Compression Parameters