Oracle® Database PL/SQL Packages and Types Reference 10g Release 2 (10.2) Part Number B14258-01 |
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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:
Overview
Security Model
Operational Notes
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.
Note:
The public synonym forDBMS_APPLICATION_INFO
is not dropped before creation so that you can redirect the public synonym to point to your own package.No further privileges are required. The DBMSAPIN.SQL
script is already run by catproc
.
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.
Table 14-1 DBMS_APPLICATION_INFO Package Subprograms
Subprogram | Description |
---|---|
READ_CLIENT_INFO Procedure |
Reads the value of the client_info field of the current session |
READ_MODULE Procedure |
Reads the values of the module and action fields of the current session |
SET_ACTION Procedure |
Sets the name of the current action within the current module |
SET_CLIENT_INFO Procedure |
Sets the client_info field of the session |
SET_MODULE Procedure |
Sets the name of the module that is currently running to a new module |
SET_SESSION_LONGOPS Procedure |
Sets a row in the V$SESSION_LONGOPS table |
This procedure reads the value of the client_info
field of the current session.
Syntax
DBMS_APPLICATION_INFO.READ_CLIENT_INFO ( client_info OUT VARCHAR2);
Parameters
Table 14-2 READ_CLIENT_INFO Procedure Parameters
Parameter | Description |
---|---|
client_info |
Last client information value supplied to the SET_CLIENT_INFO procedure. |
This procedure reads the values of the module and action fields of the current session.
Syntax
DBMS_APPLICATION_INFO.READ_MODULE ( module_name OUT VARCHAR2, action_name OUT VARCHAR2);
Parameters
Table 14-3 READ_MODULE Procedure Parameters
Parameter | Description |
---|---|
module_name |
Last value that the module name was set to by calling SET_MODULE . |
action_name |
Last value that the action name was set to by calling SET_ACTION or SET_MODULE . |
Usage Notes
Module and action names for a registered application can be retrieved by querying V$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.
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 14-4 SET_ACTION Procedure Parameters
Parameter | Description |
---|---|
action_name |
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 NULL if there is not. Names longer than 32 bytes are truncated. |
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;
This procedure supplies additional information about the client application.
Syntax
DBMS_APPLICATION_INFO.SET_CLIENT_INFO ( client_info IN VARCHAR2);
Parameters
Table 14-5 SET_CLIENT_INFO Procedure Parameters
Parameter | Description |
---|---|
client_info |
Supplies any additional information about the client application. This information is stored in the V$SESSION view. Information exceeding 64 bytes is truncated. |
Note:
CLIENT_INFO
is readable and writable by any user. For storing secured application attributes, you can use the application context feature.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 14-6 SET_MODULE Procedure Parameters
Parameter | Description |
---|---|
module_name |
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 NULL if there is not. Names longer than 48 bytes are truncated. |
action_name |
Name of current action within the current module. If you do not want to specify an action, this value should be NULL . Names longer than 32 bytes are truncated. |
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;
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 14-7 SET_SESSION_LONGOPS Procedure Parameters
Parameter | Description |
---|---|
rindex |
A token which represents the v$session_longops row to update. Set this to set_session_longops_nohint to start a new row. Use the returned value from the prior call to reuse a row. |
slno |
Saves information across calls to set_session_longops : It is for internal use and should not be modified by the caller. |
op_name |
Specifies the name of the long running task. It appears as the OPNAME column of v$session_longops . The maximum length is 64 bytes. |
target |
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 TARGET column of v$session_longops . |
context |
Any number the client wants to store. It appears in the CONTEXT column of v$session_longops . |
sofar |
Any number the client wants to store. It appears in the SOFAR column of v$session_longops . This is typically the amount of work which has been done so far. |
totalwork |
Any number the client wants to store. It appears in the TOTALWORK column of v$session_longops . This is typically an estimate of the total amount of work needed to be done in this long running operation. |
target_desc |
Specifies the description of the object being manipulated in this long operation. This provides a caption for the target parameter. This value appears in the TARGET_DESC field of v$session_longops . The maximum length is 32 bytes. |
units |
Specifies the units in which sofar and totalwork are being represented. It appears as the UNITS field of v$session_longops . The maximum length is 32 bytes. |
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;