CREATE LIBRARY Statement

14.8 CREATE LIBRARY Statement

The CREATE LIBRARY statement creates a library, which is a schema object associated with an operating-system shared library.

Note:

The CREATE LIBRARY statement is valid only on platforms that support shared libraries and dynamic linking.

For instructions for creating an operating-system shared library, or DLL, see Oracle Database Development Guide.

You can use the name of the library schema object in the call_spec of CREATE FUNCTION or CREATE PROCEDURE statements, or when declaring a function or procedure in a package or type, so that SQL and PL/SQL can invoke third-generation-language (3GL) functions and procedures.

Topics

Prerequisites

To create a library in your schema, you must have the CREATE LIBRARY system privilege. To create a library in another user's schema, you must have the CREATE ANY LIBRARY system privilege.

To create a library that is associated with a DLL in a directory object, you must have the EXECUTE object privilege on the directory object.

To create a library that is associated with a credential name, you must have the EXECUTE object privilege on the credential name.

To use the library in the call_spec of a CREATE FUNCTION statement, or when declaring a function in a package or type, you must have the EXECUTE object privilege on the library and the CREATE FUNCTION system privilege.

To use the library in the call_spec of a CREATE PROCEDURE statement, or when declaring a procedure in a package or type, you must have the EXECUTE object privilege on the library and the CREATE PROCEDURE system privilege.

To execute a procedure or function defined with the call_spec (including a procedure or function defined within a package or type), you must have the EXECUTE object privilege on the procedure or function (but you do not need the EXECUTE object privilege on the library).

Syntax

create_library ::=

Description of the illustration create_library.eps

plsql_library_source ::=

Description of the illustration plsql_library_source.eps

(sharing_clause ::=)

Semantics

create_library

OR REPLACE

Re-creates the library if it exists, and recompiles it.

Users who were granted privileges on the library before it was redefined can still access it without being regranted the privileges.

[ EDITIONABLE | NONEDITIONABLE ]

Specifies whether the library is an editioned or noneditioned object if editioning is enabled for the schema object type LIBRARY in schema. Default: EDITIONABLE. For information about editioned and noneditioned objects, see Oracle Database Development Guide.

plsql_library_source

schema

Name of the schema containing the library. Default: your schema.

library_name

Name that represents this library when a user declares a function or procedure with a call_spec.

'full_path_name'

String literal enclosed in single quotation marks, whose value your operating system recognizes as the full path name of a shared library.

The full_path_name is not interpreted during execution of the CREATE LIBRARY statement. The existence of the shared library is checked when someone invokes one of its subprograms.

'file_name' IN directory_object

The file_name is a string literal enclosed in single quotation marks, whose value is the name of a dynamic link library (DLL) in directory_object. The string literal cannot exceed 2,000 bytes and cannot contain path delimiters. The compiler ignores file_name, but at run time, file_name is checked for path delimiters.

directory_object

The directory_object is a directory object, created with the CREATE DIRECTORY statement (described in Oracle Database SQL Language Reference). If directory_object does not exist or you do not have the EXECUTE object privilege on directory_object, then the library is created with errors. If directory_object is subsequently created, then the library becomes invalid. Other reasons that the library can become invalid are:

directory_object is dropped.
directory_object becomes invalid.
Your EXECUTE object privilege on directory_object is revoked.

AGENT 'agent_dblink'

Causes external procedures to run from a database link other than the server. Oracle Database uses the database link that agent_dblink specifies to run external procedures. If you omit this clause, then the default agent on the server (extproc) runs external procedures.

CREDENTIAL [schema.]credential_name

Specifies the credentials of the operating system user that the extproc agent impersonates when running an external subprogram that specifies the library. Default: Owner of the Oracle Database installation.

If credential_name does not exist or you do not have the EXECUTE object privilege on credential_name, then the library is created with errors. If credential_name is subsequently created, then the library becomes invalid. Other reasons that the library can become invalid are:

credential_name is dropped.
credential_name becomes invalid.
Your EXECUTE object privilege on credential_name is revoked.

For information about using credentials, see Oracle Database Security Guide.

Examples

Example 14-17 Creating a Library

The following statement creates library ext_lib, using a directory object:

CREATE LIBRARY ext_lib AS 'ddl_1' IN ddl_dir;
/

The following statement re-creates library ext_lib, using a directory object and a credential:

CREATE OR REPLACE LIBRARY ext_lib AS 'ddl_1' IN ddl_dir CREDENTIAL ddl_cred;
/

The following statement creates library ext_lib, using an explicit path:

CREATE LIBRARY ext_lib AS '/OR/lib/ext_lib.so';
/

The following statement re-creates library ext_lib, using an explicit path:

CREATE OR REPLACE LIBRARY ext_lib IS '/OR/newlib/ext_lib.so';
/

Example 14-18 Specifying an External Procedure Agent

The following example creates a library app_lib (using an explicit path) and specifies that external procedures run from the public database sales.hq.example.com:

CREATE LIBRARY app_lib as '${ORACLE_HOME}/lib/app_lib.so'
   AGENT 'sales.hq.example.com';
/