SQL QUERTY WITH TEXT 'SAVEPOINT FM_1' consumes lot of CPU

Question

WE ARE USING ORACLE DATABASE 10g Rel 1
and Oracle Application server 10g
WHEN WE check Top SQL the top most seql with Activity % and CPU % of
45% is a SQL Which has following query
'SAVEPOINT FM_1'
What is this ?
Chaand

Answer 1

Hi,
A savepoint is a point in a transaction when you set a "mark". Further ni the transation you can ROLLBACK TO a savepoint instead of rolling back to the transaction beginning. Look at this sample:
TEST> CREATE TABLE A
  2  (
  3  I NUMBER
  4  );
Table created.
TEST> INSERT INTO A VALUES (1);
1 row created.
TEST> COMMIT;
Commit complete.
TEST> -- here it's a new transaction.
TEST> INSERT INTO A VALUES (2);
1 row created.
TEST>-- here, i set a savepoint. Hence the table state is that it contains values (1,2).
TEST> SAVEPOINT S1;
Savepoint created.
TEST> -- I add a new value which is in a diferent "transaction step/environment"
TEST> INSERT INTO A VALUES (3);
1 row created.
TEST> -- And I get the 3 values as expected.
TEST> SELECT * FROM A;
         I
         1
         2
         3
TEST> -- Then when I rollback to the savepoint
TEST> ROLLBACK TO S1;
Rollback complete.
TEST> -- And then commit
TEST> COMMIT;
Commit complete.
TEST> -- The transaction part beween S1 and the ROLLBACK TO has "never existed"
TEST> -- And as I have commited, the transaction part beween the begin of the transaction (first commit)
TEST> -- and the savepoint is commited.
TEST> -- Which we can see by:
TEST> SELECT * FROM A;
         I
         1
         2HTH,
Yoann.