Skip to main content

Question 12: What is PRAGMA AUTONOMOUS_TRANSACTION?

You are running a pl/sql block or procedure called parent

In that procedure you called another one procedure namely child and that procedure contains commit statement.

After calling the child procedure the transactions done in parent procedure are also committed due to the child procedure commit statement.

But you want to rollback or commit the parent procedure whole transactions based on your requirement after the calling procedure child.

In this situation, you should add the "pragma autonomus transaction" in child procedure.
If you add this statement then it acts as a separate. If you use commit in child procedure it will not affect the parent procedure.

Example :
CREATE OR REPLACE PROCEDURE parent()
AS
BEGIN
UPDATE tab1 SET fieldname = value WHERE condition;
UPDATE tab2 SET fieldname = value WHERE condition;
child();
UPDATE tab4 SET fieldname = value WHERE condition;
IF parentcondition
COMMIT;
ELSE
ROLLBACK;
END IF;
END.

CREATE OR REPLACE PROCEDURE child()
AS
PRAGMA AUTONOMOUS_TRANSACTION;
BEGIN
UPDATE tab3 SET fieldname = value WHERE condition;
COMMIT;
END.


In above case tab1, tab2 and tab4 tables transactions will commit or rollback based on the parentcondition. but tab3 updation will always commits, that is not consider the parent procedure.

lot of interview quesitions and answers, objective type questions with answers also available. To see click http://atchaya.com/ora/orahome.html

Labels:

Comments

Post a Comment

Popular posts from this blog

Question 8: Aggregate Functions

Examine the description of the STUDENTS table: STD_ID NUMBER(4) COURSE_ID VARCHARD2(10) START_DATE DATE END_DATE DATE Which two aggregate functions are valid on the START_DATE column? (Choose two) A. SUM(start_date) B. AVG(start_date) C. COUNT(start_date) D. AVG(start_date, end_date) E. MIN(start_date) F. MAXIMUM(start_date) Answer: C & E Explanation: It is possible to apply COUNT() and MIN() functions on the column with DATE data type. Incorrect Answers A: Function SUM() cannot be used with DATE data type column. B: Function AVG() cannot be used with DATE data type column. D: Function AVG() cannot be used with DATE data type column, and function AVG() just has one parameter X, not two. It averages all X column values returned by the SELECT statement. F: There is no MAXIMUM() function in Oracle, only MAX() function exists.
Post a Comment
Read more

18. ADDING CHECK CONSTRAINT WHILE INSERTING.

Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER NOT NULL EMP_NAME VARCHAR2(30) JOB_ID VARCHAR2(20) SAL NUMBER MGR_ID NUMBER DEPARTMENT_ID NUMBER You want to create a SQL script file that contains an INSERT statement. When the script is run, the INSERT statement should insert a row with the specified values into the EMPLOYEES table. The INSERT statement should pass values to the table columns as specified below: EMPLOYEE_ID: Next value from the sequence EMP_ID_SEQEMP_NAME and JOB_ID: As specified by the user during run time, through substitution variables SAL: 2000 MGR_ID: No value DEPARTMENT_ID: Supplied by the user during run time throughsubstitutionvariable. The INSERT statement should fail if the user supplies a value other than20 or 50. Which INSERT statement meets the above requirements? A. INSERT INTO employees VALUES (emp_id_seq.NEXTVAL, '&ename', '&jobid', 2000, NULL,&did); B. INSERT INTO employees VALUES (emp_id_seq.NEXTVAL, '...
Post a Comment
Read more

19. Oracle Processes

Processes Oracle uses many small (focused) processes to manage and control the Oracle instance. This allows for optimum execution on multi-processor systems using multi-core and multi-threaded technology. Some of these processes include: PMON - Process Monitor SMON - System Monitor ARCn - Redo Log Archiver LGWR - Redo Log Writer DBWn - Database Writer CKPT - Checkpoint process RECO - Recoverer CJQn - Job Queue Coordinator QMNn - Queue-monitor processes Dnnn - Dispatcher Processes (multiplex server-processes on behalf of users) Snnn - Shared server processes (serve client-requests) MMAN - Internal process (used for internal database tasks) LSP0 - Logical standby coordinator process (controls Data Guard log-application) MRP - Media-recovery process (detached recovery-server process) MMON - Memory-monitor process MMNL - Memory monitor light (gathers and stores AWR statistics) PSP0 - Process-spawner (spawns Oracle processes) RFS - Remote file server process (archive to a remote site) DBRM ...
Post a Comment
Read more