DBMS_MLE

117 DBMS_MLE

The DBMS_MLE package allows users to execute JavaScript code inside the Oracle Database and exchange data seamlessly between PL/SQL and JavaScript. The JavaScript code itself can execute PL/SQL and SQL through built-in JavaScript modules. JavaScript data types are automatically mapped to Oracle Database data types and vice versa.

With the DBMS_MLE package, developers can write their data processing logic in JavaScript.

This chapter contains the following topics:

117.1 DBMS_MLE Overview

Runtime state for MLE execution is encapsulated in execution contexts that users can explicitly create and destroy. Users can also export values from PL/SQL to MLE, and import values from MLE back into PL/SQL.

The following example captures the typical workflow for MLE execution:

set serveroutput on;
declare
  ctx dbms_mle.context_handle_t;
  source clob;
  greeting varchar2(100);
begin
  ctx := dbms_mle.create_context(); -- Create execution context for MLE execution
  dbms_mle.export_to_mle(ctx, 'person', 'World'); -- Export value from PL/SQL
  source := q'~
    var bindings = require("mle-js-bindings");
    var person = bindings.importValue("person"); // Import value previously exported from PL/SQL
    var greeting = "Hello, " + person + "!";
    bindings.exportValue("greeting", greeting); // Export value to PL/SQL
  ~';
  dbms_mle.eval(ctx, 'JAVASCRIPT', source); -- Evaluate the source code snippet in the execution context
  dbms_mle.import_from_mle(ctx, 'greeting', greeting); -- Import value previously exported from MLE
  dbms_output.put_line('Greetings from MLE: ' || greeting);
  dbms_mle.drop_context(ctx); -- Drop the execution context once no longer required
end;
/

Executing the above code block produces the following output:

Greetings from MLE: Hello, World!

117.2 DBMS_MLE Security Model

Access to MLE features is protected by database privileges. The user must have the EXECUTE DYNAMIC MLE privilege while calling any of its functions and procedures that pertain to MLE execution. In addition to this, the user must also have the EXECUTE privilege on an MLE language (for example, EXECUTE ON JAVASCRIPT) to execute code in that language. An ORA-01031 error is raised if the user calling any of the DBMS_MLE subprograms does not have the appropriate privileges. See the summary of DBMS_MLE subprograms for the privileges required to call each DBMS_MLE subprogram.

117.3 Summary of DBMS_MLE Subprograms

This table lists the DBMS_MLE subprograms and briefly describes them.

Table 117-1 DBMS_MLE Package Subprograms

Subprogram	Description
CREATE_CONTEXT Function	Creates an MLE context for executing snippets in any MLE language.
DISABLE_CTX_STDERR Procedure	This procedure disables stderr stream of the specified MLE context, so that future writes to stderr are discarded.
DISABLE_CTX_STDOUT Procedure	This procedure disables stdout stream of the specified MLE context, so that future writes to `stdout` are discarded.
DISABLE_STDERR Procedure	This procedure disables the stderr stream of all MLE contexts, so that future writes to `stderr` are discarded.
DISABLE_STDOUT Procedure	This procedure disables the stdout stream of all MLE contexts, so that future writes to stdout are discarded.
DROP_CONTEXT Procedure	This procedure is used to drop an MLE context that was previously created using the `CREATE_CONTEXT` procedure. After the context is dropped, the context handle is no longer valid and cannot be used anymore.
EVAL Procedure	This procedure executes the given MLE language code within the context identified by the context handle.
EXPORT_TO_MLE Procedure	This procedure allows you to assign the given value, with appropriate conversion, to the named property in the MLE context. The property is created if it is not already present.
GET_AVAILABLE_LANGUAGES Function	This function returns the set of available MLE languages.
GET_CTX_ERROR_STACK Function	This function retrieves the MLE language stack trace for the most recent application error in the given execution context.
IMPORT_FROM_MLE Procedure	This procedure retrieves the value of the named property from the MLE context and converts it to the requested PL/SQL type.
SET_CTX_STDERR Procedure	This procedure redirects the stderr stream of the MLE context to the given `CLOB`.
SET_CTX_STDERR_TO_DBMS_OUTPUT Procedure	This procedure redirects the stderr stream of the MLE context to `DBMS_OUTPUT`.
SET_CTX_STDOUT Procedure	This procedure redirects the stdout stream of the MLE context to the given `CLOB`.
SET_CTX_STDOUT_TO_DBMS_OUTPUT Procedure	This procedure redirects the stdout stream of the MLE context to `DBMS_OUTPUT`.
SET_STDERR Procedure	This procedure redirects the stderr stream of all MLE contexts to the given `CLOB`.
SET_STDERR_TO_DBMS_OUTPUT Procedure	This procedure redirects the stderr stream of all MLE contexts to `DBMS_OUTPUT`.
SET_STDOUT Procedure	This procedure redirects the stdout stream of all MLE contexts to the given `CLOB`.
SET_STDOUT_TO_DBMS_OUTPUT Procedure	This procedure redirects the stdout stream of all MLE contexts to `DBMS_OUTPUT`.

117.3.1 CREATE_CONTEXT Function

Creates an MLE context for executing snippets in any MLE language. You need the EXECUTE DYNAMIC MLE privilege to execute this function.

Syntax

DBMS_MLE.CREATE_CONTEXT
 RETURN CONTEXT_HANDLE_T;

Return Values

This function returns a handle that uniquely identifies a context within a session for use in subsequent operations, such as EXPORT_TO_MLE and EVAL.

Usage Notes

A context has a lifetime limited to the session in which it was created. When a client session is terminated, all its contexts are dropped. All MLE contexts created in a session are also dropped when the session state is reset, for example, by calling DBMS_SESSION.RESET_PACKAGE. MLE language code is evaluated in the context using the user, roles, and schema that are in effect at the time of context creation.

The procedure may raise the ORA-01031 error if the caller does not have sufficient privileges.

117.3.2 DISABLE_CTX_STDERR Procedure

This procedure disables stderr stream of the specified MLE context, so that future writes to stderr are discarded. You need the EXECUTE DYNAMIC MLE privilege to execute this function.

Syntax

DBMS_MLE.DISABLE_CTX_STDERR(
      context_handle            IN            context_handle_t);

Parameters

Table 117-2 DISABLE_CTX_STDERR Procedure Parameters

Parameter	Description
`context_handle`	The handle to an MLE context in the current session.

Usage Notes

Any output that was buffered so far gets flushed to the pre-existing sink.

The procedure may raise the following errors:

ORA-01031: if the caller does not have sufficient privileges

117.3.3 DISABLE_CTX_STDOUT Procedure

This procedure disables stdout stream of the specified MLE context, so that future writes to stdout are discarded. You need the EXECUTE DYNAMIC MLE privilege to execute this function.

Syntax

DBMS_MLE.DISABLE_CTX_STDOUT(
      context_handle            IN            context_handle_t);

Parameters

Table 117-3 DISABLE_CTX_STDOUT Procedure Parameters

Parameter	Description
`context_handle`	The handle to an MLE context in the current session.

Usage Notes

Any output that was buffered so far gets flushed to the pre-existing sink.

The procedure may raise the following errors:

ORA-01031: if the caller does not have sufficient privileges

117.3.4 DISABLE_STDERR Procedure

This procedure disables the stderr stream of all MLE contexts, so that future writes to stderr are discarded. This applies to all existing contexts and contexts created in the future. You need the EXECUTE DYNAMIC MLE privilege to execute this function.

Syntax

DBMS_MLE.DISABLE_STDERR();

Usage Notes

Any output that was buffered so far gets flushed to the pre-existing sink.

The procedure may raise the following errors:

ORA-01031: if the caller does not have sufficient privileges

117.3.5 DISABLE_STDOUT Procedure

This procedure disables the stdout stream of all MLE contexts, so that future writes to stdout are discarded. This applies to all existing contexts and contexts created in the future. You need the EXECUTE DYNAMIC MLE privilege to execute this function.

Syntax

DBMS_MLE.DISABLE_STDOUT();

Usage Notes

Any output that was buffered so far gets flushed to the pre-existing sink.

The procedure may raise the following errors:

ORA-01031: if the caller does not have sufficient privileges

117.3.6 DROP_CONTEXT Procedure

This procedure is used to drop an MLE context that was previously created using the CREATE_CONTEXT function. After the context is dropped, the context handle is no longer valid and cannot be used anymore. You need the EXECUTE DYNAMIC MLE privilege to execute this procedure.

Syntax

DBMS_MLE.DROP_CONTEXT(
   context_handle   IN      context_handle_t);

Parameters

Table 117-4 DROP_CONTEXT Procedure Parameters

Parameter	Description
`context_handle`	The handle to an MLE context in the current session.

Usage Notes

The procedure may raise ORA-01031 error if the caller does not have sufficient privileges.

117.3.7 EVAL Procedure

This procedure executes the given MLE language code within the context identified by the context handle.

The evaluated code has access to all previous modifications to the state of the context, including variables defined by code previously evaluated in the context and values exported through EXPORT_TO_MLE(). The evaluated code can also import MLE built-in modules such as the MLE SQL driver.

You need the EXECUTE DYNAMIC MLE privilege to execute this procedure. It also requires the EXECUTE privilege for the given language, for example, EXECUTE ON JAVASCRIPT.

Syntax

DBMS_MLE.EVAL(
   context_handle   IN         context_handle_t,
   language_id      IN         language_t,
   source           IN         CLOB,
   result           IN OUT     NOCOPY CLOB CHARACTER SET ANY_CS);

DBMS_MLE.EVAL(
   context_handle   IN         context_handle_t,
   language_id      IN         language_t,
   source           IN         VARCHAR2,
   result           IN OUT     NOCOPY CLOB CHARACTER SET ANY_CS);

DBMS_MLE.EVAL(
   context_handle   IN         context_handle_t,
   language_id      IN         language_t,
   source           IN         CLOB);

DBMS_MLE.EVAL(
   context_handle   IN         context_handle_t,
   language_id      IN         language_t,
   source           IN         VARCHAR2);

Parameters

Table 117-5 EVAL Procedure Parameters

Parameter	Description
`context_handle`	The handle to an MLE context.
`language_id`	The language of the provided source code. For example, JavaScript.
`source`	The source code to be executed.
`result`	A non-NULL buffer to which the result of the evaluation of the source code is appended.

Usage Notes

The procedure may raise the following errors:

ORA-01031: if the caller does not have sufficient privileges
ORA-04108: if the current container, the current user, or the currently enabled roles are different from those in effect at the time of context creation.

117.3.8 EXPORT_TO_MLE Procedure

This procedure allows you to assign the given value, with appropriate conversion, to the named property in the MLE context. The property is created if it is not already present. You need the EXECUTE DYNAMIC MLE privilege to execute this function.

Syntax

DBMS_MLE.EXPORT_TO_MLE (
   context_handle   IN      context_handle_t,
   property_name    IN      VARCHAR2,
   property_value   IN      BINARY_INTEGER);

DBMS_MLE.EXPORT_TO_MLE (
   context_handle   IN      context_handle_t,
   property_name    IN      VARCHAR2,
   property_value   IN      BINARY_DOUBLE);

DBMS_MLE.EXPORT_TO_MLE (
   context_handle   IN      context_handle_t,
   property_name    IN      VARCHAR2,
   property_value   IN      BINARY_FLOAT);

DBMS_MLE.EXPORT_TO_MLE (
   context_handle   IN      context_handle_t,
   property_name    IN      VARCHAR2,
   property_value   IN      BLOB);

DBMS_MLE.EXPORT_TO_MLE (
   context_handle   IN      context_handle_t,
   property_name    IN      VARCHAR2,
   property_value   IN      BOOLEAN);

DBMS_MLE.EXPORT_TO_MLE (
   context_handle   IN      context_handle_t,
   property_name    IN      VARCHAR2,
   property_value   IN      CLOB CHARACTER SET ANY_CS);

DBMS_MLE.EXPORT_TO_MLE (
   context_handle   IN      context_handle_t,
   property_name    IN      VARCHAR2,
   property_value   IN      DATE);

DBMS_MLE.EXPORT_TO_MLE (
   context_handle   IN      context_handle_t,
   property_name   IN      VARCHAR2,
   property_value   IN      DSINTERVAL_UNCONSTRAINED);

DBMS_MLE.EXPORT_TO_MLE (
   context_handle   IN      context_handle_t,
   property_name   IN      VARCHAR2,
   property_value   IN      NUMBER);

DBMS_MLE.EXPORT_TO_MLE (
   context_handle   IN      context_handle_t,
   property_name   IN      VARCHAR2,
   property_value   IN      TIMESTAMP_TZ_UNCONSTRAINED);

DBMS_MLE.EXPORT_TO_MLE (
   context_handle   IN      context_handle_t,
   property_name   IN      VARCHAR2,
   property_value   IN      TIMESTAMP_UNCONSTRAINED);

DBMS_MLE.EXPORT_UROWID (
   context_handle   IN      context_handle_t,
   property_name   IN      VARCHAR2,
   property_value   IN      UROWID);

DBMS_MLE.EXPORT_TO_MLE (
   context_handle   IN      context_handle_t,
   property_name   IN      VARCHAR2,
   property_value   IN      VARCHAR2 CHARACTER SET ANY_CS);

DBMS_MLE.EXPORT_TO_MLE (
   context_handle   IN      context_handle_t,
   property_name   IN      VARCHAR2,
   property_value   IN      YMINTERVAL_UNCONSTRAINED);

DBMS_MLE.EXPORT_CHAR (
   context_handle   IN      context_handle_t,
   property_name   IN      VARCHAR2,
   property_value   IN      CHAR CHARACTER SET ANY_CS);

DBMS_MLE.EXPORT_RAW (
   context_handle   IN      context_handle_t,
   property_name   IN      VARCHAR2,
   property_value   IN      RAW);

Parameters

Table 117-6 EXPORT_TO_MLE Procedure Parameters

Parameter	Description
`context_handle`	The handle to an MLE context in the current session.
`property_name`	The name of the variable to be set. If the `property_name` value is `NULL` or an empty string, `ORA-04157` error is thrown.
`property_value`	The value to which the variable should be set.

Usage Notes

The procedure may raise the following errors:

ORA-01031: if the caller does not have sufficient privileges.
ORA-04157: if the value of the passed property_name is NULL or an empty string.
ORA-04108: if the current container, the current user, or the currently enabled roles are different from those in effect at the time of context creation.

117.3.9 GET_AVAILABLE_LANGUAGES Function

This function returns the set of available MLE languages.

Syntax

DBMS_MLE.GET_AVAILABLE_LANGUAGES()
  RETURN languages_t;

Return Values

A set of available MLE languages as a table of language identifiers as they can be used as an argument to DBMS_MLE.EVAL().

117.3.10 GET_CTX_ERROR_STACK Function

This function retrieves the MLE language stack trace for the most recent application error in the given execution context. You need the EXECUTE DYNAMIC MLE privilege to execute this function.

Syntax

DBMS_MLE.GET_CTX_ERROR_STACK(
      context_handle            IN            context_handle_t)
RETURN error_frames_t;

Parameters

Table 117-7 GET_CTX_ERROR_STACK Function Parameters

Parameter	Description
`context_handle`	The handle to an MLE context in the current session.

Return Values

A collection of error stack frames, each of type error_frame_t. An empty collection is returned if there is no error stack to report.

Usage Notes

The Function may raise the following errors:

ORA-01031: if the caller does not have sufficient privileges

117.3.11 IMPORT_FROM_MLE Procedure

This procedure retrieves the value of the named property from the MLE context and converts it to the requested PL/SQL type. You need the EXECUTE DYNAMIC MLE privilege to execute this procedure.

Syntax

DBMS_MLE.IMPORT_FROM_MLE (
   context_handle   IN      context_handle_t,
   property_name    IN      VARCHAR2,
   target           OUT     NOCOPY BINARY_INTEGER);

DBMS_MLE.IMPORT_FROM_MLE (
   context_handle   IN      context_handle_t,
   property_name    IN      VARCHAR2,
   target           OUT     NOCOPY BINARY_DOUBLE);

DBMS_MLE.IMPORT_FROM_MLE (
   context_handle   IN      context_handle_t,
   property_name    IN      VARCHAR2,
   target           OUT     NOCOPY BINARY_FLOAT);

DBMS_MLE.IMPORT_FROM_MLE (
   context_handle   IN      context_handle_t,
   property_name    IN      VARCHAR2,
   target           OUT     NOCOPY BLOB);

DBMS_MLE.IMPORT_FROM_MLE (
   context_handle   IN      context_handle_t,
   property_name    IN      VARCHAR2,
   target           OUT     NOCOPY BOOLEAN);

DBMS_MLE.IMPORT_FROM_MLE (
   context_handle   IN      context_handle_t,
   property_name    IN      VARCHAR2,
   target           OUT     NOCOPY CLOB CHARACTER SET ANY_CS);

DBMS_MLE.IMPORT_FROM_MLE (
   context_handle   IN      context_handle_t,
   property_name    IN      VARCHAR2,
   target           OUT     NOCOPY DATE);

DBMS_MLE.IMPORT_FROM_MLE (
   context_handle   IN      context_handle_t,
   property_name    IN      VARCHAR2,
   target           OUT     NOCOPY DSINTERVAL_UNCONSTRAINED);

DBMS_MLE.IMPORT_FROM_MLE (
   context_handle   IN      context_handle_t,
   property_name   IN      VARCHAR2,
   target            OUT   NOCOPY NUMBER);

DBMS_MLE.IMPORT_FROM_MLE (
   context_handle   IN      context_handle_t,
   property_name   IN      VARCHAR2,
   target            OUT   NOCOPY TIMESTAMP_TZ_UNCONSTRAINED);

DBMS_MLE.IMPORT_FROM_MLE (
   context_handle   IN      context_handle_t,
   property_name   IN      VARCHAR2,
   target            OUT   NOCOPY TIMESTAMP_UNCONSTRAINED);

DBMS_MLE.IMPORT_UROWID (
   context_handle   IN      context_handle_t,
   property_name   IN      VARCHAR2,
   target            OUT   NOCOPY UROWID);

DBMS_MLE.IMPORT_FROM_MLE (
   context_handle   IN      context_handle_t,
   property_name   IN      VARCHAR2,
   target            OUT   NOCOPY VARCHAR2 CHARACTER SET ANY_CS);

DBMS_MLE.IMPORT_FROM_MLE (
   context_handle   IN      context_handle_t,
   property_name   IN      VARCHAR2,
   target            OUT   NOCOPY YMINTERVAL_UNCONSTRAINED);

DBMS_MLE.IMPORT_CHAR (
   context_handle   IN      context_handle_t,
   property_name   IN      VARCHAR2,
   target            OUT   CHAR CHARACTER SET ANY_CS);

DBMS_MLE.IMPORT_RAW (
   context_handle   IN      context_handle_t,
   property_name   IN      VARCHAR2,
   target            OUT   RAW);

Parameters

Table 117-8 IMPORT_FROM_MLE Procedure Parameters

Parameter	Description
`context_handle`	The handle to an MLE context in the current session.
`property_name`	The name of the property to be retrieved. If the `property_name` is `NULL` or an empty string, `ORA-04157` error is thrown.
`target`	A PL/SQL variable into which the retrieved property is stored.

Usage Notes

The IMPORT_FROM_MLE procedure may throw the following exceptions:

ORA-01031: if the caller does not have sufficient privileges.
ORA-04108: if the current container, the current user, or the currently enabled roles are different from those in effect at the time of context creation.
ORA-04157: if the value of the passed property_name is NULL or an empty string.
ORA-04205: the value cannot be converted to the target PL/SQL type.
ORA-06502: the buffer of the PL/SQL variable is too small to hold the retrieved value.

117.3.12 SET_CTX_STDERR Procedure

This procedure redirects the stderr stream of the MLE context to the given CLOB. You need the EXECUTE DYNAMIC MLE privilege to execute this function.

Syntax

DBMS_MLE.SET_CTX_STDERR(
      context_handle  IN            context_handle_t,
      sink            IN OUT        NOCOPY CLOB CHARACTER SET ANY_CS);

Parameters

Table 117-9 SET_CTX_STDERR Procedure Parameters

Parameter	Description
`context_handle`	Handle to an MLE context in the current session.
`sink`	The CLOB sink to redirect stderr to. Providing a `NULL` value will result in `ORA-06530` error.

Usage Notes

Any output that was buffered so far gets flushed to the pre-existing sink before redirecting to the new sink.

The procedure may raise the following errors:

ORA-01031: if the caller does not have sufficient privileges
ORA-06530: if the sink is NULL.

117.3.13 SET_CTX_STDERR_TO_DBMS_OUTPUT Procedure

This procedure redirects the stderr stream of the MLE context to DBMS_OUTPUT. You need the EXECUTE DYNAMIC MLE privilege to execute this function.

Syntax

DBMS_MLE.SET_CTX_STDERR_TO_DBMS_OUTPUT(
   context_handle      IN      context_handle_t);

Parameters

Table 117-10 SET_CTX_STDERR_TO_DBMS_OUTPUT Procedure Parameters

Parameter	Description
`context_handle`	Handle to an MLE context in the current session.

Usage Notes

Any output that was buffered so far gets flushed to the pre-existing sink before redirecting to DBMS_OUTPUT.

The procedure may raise the following errors:

ORA-01031: if the caller does not have sufficient privileges

117.3.14 SET_CTX_STDOUT Procedure

This procedure redirects the stdout stream of the MLE context to the given CLOB. You need the EXECUTE DYNAMIC MLE privilege to execute this function.

Syntax

DBMS_MLE.SET_CTX_STDOUT(
   context_handle      IN context_handle_t,
   sink                IN OUT NOCOPY CLOB CHARACTER SET ANY_CS);

Parameters

Table 117-11 SET_CTX_STDOUT Procedure Parameters

Parameter	Description
`context_handle`	The handle to an MLE context in the current session.
`sink`	The `CLOB` to redirect `stdout` to. Providing a `NULL` value will result in `ORA-06530` error.

Usage Notes

Any output that was buffered so far gets flushed to the pre-existing sink before redirecting to the new sink.

This procedure may raise the following errors:

ORA-01031: if the caller does not have sufficient privileges
ORA-06530: if the sink is NULL.

117.3.15 SET_CTX_STDOUT_TO_DBMS_OUTPUT Procedure

This procedure redirects the stdout stream of the MLE context to DBMS_OUTPUT. You need the EXECUTE DYNAMIC MLE privilege to execute this function.

Syntax

DBMS_MLE.SET_CTX_STDOUT_TO_DBMS_OUTPUT(
   context_handle      IN      context_handle_t);

Parameters

Table 117-12 SET_CTX_STDOUT_TO_DBMS_OUTPUT Procedure Parameters

Parameter	Description
`context_handle`	The handle to an MLE context in the current session.

Usage Notes

Any output that was buffered so far gets flushed to the pre-existing sink before redirecting to DBMS_OUTPUT.

The procedure may raise the following errors:

ORA-01031: if the caller does not have sufficient privileges

117.3.16 SET_STDERR Procedure

This procedure redirects the stderr stream of all MLE contexts to the given CLOB. This applies to all existing contexts and contexts created in the future. You need the EXECUTE DYNAMIC MLE privilege to execute this function.

Syntax

DBMS_MLE.SET_STDERR(
      sink            IN OUT       NOCOPY CLOB CHARACTER SET ANY_CS);

Parameters

Table 117-13 SET_STDERR Procedure Parameters

Parameter	Description
`sink`	The CLOB to redirect `stdout` to.

Usage Notes

Any output that was buffered so far gets flushed to the pre-existing sink before redirecting to the new sink.

The procedure may raise the following errors:

ORA-01031: if the caller does not have sufficient privileges
ORA-06530: if the sink is NULL.

117.3.17 SET_STDERR_TO_DBMS_OUTPUT Procedure

This procedure redirects the stderr stream of all MLE contexts to DBMS_OUTPUT. This applies to all existing contexts and contexts created in the future. You need the EXECUTE DYNAMIC MLE privilege to execute this function.

Syntax

DBMS_MLE.SET_STDERR_TO_DBMS_OUTPUT();

Usage Notes

Any output that was buffered so far gets flushed to the pre-existing sink before redirecting to DBMS_OUTPUT.

The procedure may raise the following errors:

ORA-01031: if the caller does not have sufficient privileges

117.3.18 SET_STDOUT Procedure

This procedure redirects the stdout stream of all MLE contexts to the given CLOB. This applies to all existing contexts and contexts created in the future. You need the EXECUTE DYNAMIC MLE privilege to execute this function.

Syntax

DBMS_MLE.SET_STDOUT(
   sink       IN OUT   NOCOPY CLOB CHARACTER SET ANY_CS);

Parameters

Table 117-14 SET_STDOUT Procedure Parameters

Parameter	Description
`sink`	The CLOB to redirect stdout to.

Usage Notes

Any output that was buffered so far gets flushed to the pre-existing sink before redirecting to the new sink.

The procedure may raise the following errors:

ORA-01031: if the caller does not have sufficient privileges
ORA-06530: if the sink is NULL.

117.3.19 SET_STDOUT_TO_DBMS_OUTPUT Procedure

This procedure redirects the stdout stream of all MLE contexts to DBMS_OUTPUT. This applies to all existing contexts and contexts created in the future. You need the EXECUTE DYNAMIC MLE privilege to execute this function.

Syntax

DBMS_MLE.SET_STDOUT_TO_DBMS_OUTPUT();

Usage Notes

Any output that was buffered so far gets flushed to the pre-existing sink before redirecting to DBMS_OUTPUT.

The procedure may raise the following errors:

ORA-01031: if the caller does not have sufficient privileges