19 DBMS_APPLICATION_INFO
Application developers can use the DBMS_APPLICATION_INFO package with Oracle Trace and the SQL trace facility to record names of executing modules or transactions in the database for later use when tracking the performance of various modules and debugging.
This chapter contains the following topics:
19.1 DBMS_APPLICATION_INFO Overview
Registering the application allows system administrators and performance tuning specialists to track performance by module. System administrators can also use this information to track resource use by module. When an application registers with the database, its name and actions are recorded in the V$SESSION and V$SQLAREA views.
19.2 DBMS_APPLICATION_INFO Security Model
No further privileges are required. The DBMSAPIN.SQL script is already run as a part of standard database creation.
Note:
The public synonym for DBMS_APPLICATION_INFO is not dropped before creation so that you can redirect the public synonym to point to your own package.
19.3 DBMS_APPLICATION_INFO Operational Notes
Your applications should set the name of the module and name of the action automatically each time a user enters that module. The module name could be the name of a form in an Oracle Forms application, or the name of the code segment in an Oracle Precompilers application. The action name should usually be the name or description of the current transaction within a module.
If you want to gather your own statistics based on module, you can implement a wrapper around this package by writing a version of this package in another schema that first gathers statistics and then calls the SYS version of the package. The public synonym for DBMS_APPLICATION_INFO can then be changed to point to the DBA's version of the package.
19.4 Summary of DBMS_APPLICATION_INFO Subprograms
This table lists and describes the DBMS_APPLICATION_INFO package subprograms.
Table 19-1 DBMS_APPLICATION_INFO Package Subprograms
| Subprogram | Description |
|---|---|
|
Reads the value of the |
|
|
Reads the values of the module and action fields of the current session |
|
|
Sets the name of the current action within the current module |
|
|
Sets the |
|
|
Sets the name of the module that is currently running to a new module |
|
|
Sets a row in the |
19.4.1 READ_CLIENT_INFO Procedure
This procedure reads the value of the client_info field of the current session.
Syntax
DBMS_APPLICATION_INFO.READ_CLIENT_INFO ( client_info OUT VARCHAR2);
Parameters
Table 19-2 READ_CLIENT_INFO Procedure Parameters
| Parameter | Description |
|---|---|
|
|
Last client information value supplied to the |
19.4.2 READ_MODULE Procedure
This procedure reads the values of the module and action fields of the current session.
Syntax
DBMS_APPLICATION_INFO.READ_MODULE ( module_name OUT VARCHAR2, action_name OUT VARCHAR2);
Parameters
Table 19-3 READ_MODULE Procedure Parameters
| Parameter | Description |
|---|---|
|
|
Last value that the module name was set to by calling |
|
|
Last value that the action name was set to by calling |
Usage Notes
Module and action names for a registered application can be retrieved by querying V$SQLAREA or by calling the READ_MODULE procedure. Client information can be retrieved by querying the V$SESSION view, or by calling the READ_CLIENT_INFO Procedure.
Examples
The following sample query illustrates the use of the MODULE and ACTION column of the V$SQLAREA.
SELECT sql_text, disk_reads, module, action FROM v$sqlarea WHERE module = 'add_employee'; SQL_TEXT DISK_READS MODULE ACTION ------------------- ---------- ------------------ ---------------- INSERT INTO emp 1 add_employee insert into emp (ename, empno, sal, mgr, job, hiredate, comm, deptno) VALUES (name, next.emp_seq, manager, title, SYSDATE, commission, department) 1 row selected.
19.4.3 SET_ACTION Procedure
This procedure sets the name of the current action within the current module.
Syntax
DBMS_APPLICATION_INFO.SET_ACTION ( action_name IN VARCHAR2);
Parameters
Table 19-4 SET_ACTION Procedure Parameters
| Parameter | Description |
|---|---|
|
|
The name of the current action within the current module. When the current action terminates, call this procedure with the name of the next action if there is one, or |
Usage Notes
The action name should be descriptive text about the current action being performed. You should probably set the action name before the start of every transaction.
Set the transaction name to NULL after the transaction completes, so that subsequent transactions are logged correctly. If you do not set the transaction name to NULL, subsequent transactions may be logged with the previous transaction's name.
Example
The following is an example of a transaction that uses the registration procedure:
CREATE OR REPLACE PROCEDURE bal_tran (amt IN NUMBER(7,2)) AS
BEGIN
-- balance transfer transaction
DBMS_APPLICATION_INFO.SET_ACTION(
action_name => 'transfer from chk to sav');
UPDATE chk SET bal = bal + :amt
WHERE acct# = :acct;
UPDATE sav SET bal = bal - :amt
WHERE acct# = :acct;
COMMIT;
DBMS_APPLICATION_INFO.SET_ACTION(null);
END; 19.4.4 SET_CLIENT_INFO Procedure
This procedure supplies additional information about the client application.
Syntax
DBMS_APPLICATION_INFO.SET_CLIENT_INFO ( client_info IN VARCHAR2);
Parameters
Table 19-5 SET_CLIENT_INFO Procedure Parameters
| Parameter | Description |
|---|---|
|
|
Supplies any additional information about the client application. This information is stored in the |
Note:
CLIENT_INFO is readable and writable by any user. For storing secured application attributes, you can use the application context feature.
19.4.5 SET_MODULE Procedure
This procedure sets the name of the current application or module.
Syntax
DBMS_APPLICATION_INFO.SET_MODULE ( module_name IN VARCHAR2, action_name IN VARCHAR2);
Parameters
Table 19-6 SET_MODULE Procedure Parameters
| Parameter | Description |
|---|---|
|
|
Name of module that is currently running. When the current module terminates, call this procedure with the name of the new module if there is one, or |
|
|
Name of current action within the current module. If you do not want to specify an action, this value should be |
Usage Notes
Example
CREATE or replace PROCEDURE add_employee(
name VARCHAR2,
salary NUMBER,
manager NUMBER,
title VARCHAR2,
commission NUMBER,
department NUMBER) AS
BEGIN
DBMS_APPLICATION_INFO.SET_MODULE(
module_name => 'add_employee',
action_name => 'insert into emp');
INSERT INTO emp
(ename, empno, sal, mgr, job, hiredate, comm, deptno)
VALUES (name, emp_seq.nextval, salary, manager, title, SYSDATE,
commission, department);
DBMS_APPLICATION_INFO.SET_MODULE(null,null);
END;19.4.6 SET_SESSION_LONGOPS Procedure
This procedure sets a row in the V$SESSION_LONGOPS view. This is a view that is used to indicate the on-going progress of a long running operation. Some Oracle functions, such as parallel execution and Server Managed Recovery, use rows in this view to indicate the status of, for example, a database backup.
Applications may use the SET_SESSION_LONGOPS procedure to advertise information on the progress of application specific long running tasks so that the progress can be monitored by way of the V$SESSION_LONGOPS view.
Syntax
DBMS_APPLICATION_INFO.SET_SESSION_LONGOPS ( rindex IN OUT BINARY_INTEGER, slno IN OUT BINARY_INTEGER, op_name IN VARCHAR2 DEFAULT NULL, target IN BINARY_INTEGER DEFAULT 0, context IN BINARY_INTEGER DEFAULT 0, sofar IN NUMBER DEFAULT 0, totalwork IN NUMBER DEFAULT 0, target_desc IN VARCHAR2 DEFAULT 'unknown target', units IN VARCHAR2 DEFAULT NULL) set_session_longops_nohint constant BINARY_INTEGER := -1;
Parameters
Table 19-7 SET_SESSION_LONGOPS Procedure Parameters
| Parameter | Description |
|---|---|
|
|
A token which represents the |
|
|
Saves information across calls to |
|
|
Specifies the name of the long running task. It appears as the |
|
|
Specifies the object that is being worked on during the long running operation. For example, it could be a table ID that is being sorted. It appears as the |
|
|
Any number the client wants to store. It appears in the |
|
|
Any number the client wants to store. It appears in the |
|
|
Any number the client wants to store. It appears in the |
|
|
Specifies the description of the object being manipulated in this long operation. This provides a caption for the |
|
|
Specifies the units in which |
Example
This example performs a task on 10 objects in a loop. As the example completes each object, Oracle updates V$SESSION_LONGOPS on the procedure's progress.
DECLARE
rindex BINARY_INTEGER;
slno BINARY_INTEGER;
totalwork number;
sofar number;
obj BINARY_INTEGER;
BEGIN
rindex := dbms_application_info.set_session_longops_nohint;
sofar := 0;
totalwork := 10;
WHILE sofar < 10 LOOP
-- update obj based on sofar
-- perform task on object target
sofar := sofar + 1;
dbms_application_info.set_session_longops(rindex, slno,
"Operation X", obj, 0, sofar, totalwork, "table", "tables");
END LOOP;
END;