DBMS_TNS

The DBMS_TNS package provides the RESOLVE_TNSNAME function to resolve a TNS name and return the corresponding Oracle Net8 connection string.

This chapter contains the following topics:

• DBMS_TNS Overview

• DBMS_TNS Security Model

• Summary of DBMS_TNS Subprograms

DBMS_TNS Overview

The DBMS_TNS package contains one function, RESOLVE_TNSNAME, which returns the resolved connect string from configured sources that have been defined in the names.directory_path parameter in the sqlnet.ora file.

The RESOLVE_TNSNAME function in this package helps you to identify interconnected databases and trace the system change number (SCN) flow across distributed databases.

See Also:

• Oracle AI Database Administrator’s Guide for more information about finding database link information

• Oracle AI Database Reference for information about the ALL_DB_LINKS data dictionary view

DBMS_TNS Security Model

You must be granted the EXECUTE privilege on the DBMS_TNS package.

Summary of DBMS_TNS Subprograms

This table lists the DBMS_TNS subprograms and briefly describes them.

Table 1 DBMS_TNS Parameters

Subprogram	Description
RESOLVE_TNSNAME Function	Returns the resolved connect string from any configured source (tnsnames, LDAP, Easy Connect) as indicated in the sqlnet.ora names.directory_path parameter)

RESOLVE_TNSNAME Function

This function returns the resolved connect string from any configured source (for example, TNS names, Lightweight Directory Access Protocol (LDAP), or Oracle Easy Connect) as indicated in the sqlnet.ora names.directory_path parameter.

Syntax

DBMS_TNS.RESOLVE_TNSNAME (
   tns_name VARCHAR2)
  RETURN VARCHAR2;

RESOLVE_TNSNAME Function Parameters

Parameter	Description
tns_name	Database address for establishing the connection

Usage Notes

• Database administrators and system management tools can explicitly call the DBMS_TNS.RESOLVE_TNSNAME function to resolve a tns_name:

• Because the resolved value can change over time, Oracle does not recommend storing or caching this value, because these kinds of values can become invalid over time.

• You can use the DBMS_TNS.RESOLVE_TNSNAME function to resolve TNS names that were referred to by other data dictionary views such as ALL_DB_LINKS and USER_DB_LINKS. In addition, you can use it to find any TNS name entry in the tnsnames.ora file.

Example

SELECT DB_LINK, DBMS_TNS.RESOLVE_TNSNAME(HOST) FROM DBA_DB_LINKS;

DB_LINK
--------------------------------------------------------------------------------
DBMS_TNS.RESOLVE_TNSNAME(HOST)
--------------------------------------------------------------------------------
US.EXAMPLE.COM
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=may))(CONNECT_DATA=(SERVICE_NAME=us.example.com)(CID=(PROGRAM=oracle)(HOST=juno)(USER=psmith))
))