What is the function of savepoint?
A savepoint is a way of implementing subtransactions (also known as nested transactions) within a relational database management system by indicating a point within a transaction that can be “rolled back to” without affecting any work done in the transaction before the savepoint was created.
What is the function of savepoint give an example?
For example, if a complete transaction has 8 DML statements, and we create a savepoint after 4 statements, then if, for some reason after the execution of 6th statement we want to rollback uptil the 4th statement, then we can easily do that and the transaction can again be executed starting from the 4th statement.
What is a savepoint inside a PL SQL block used for?
The use of the SAVEPOINT command allows you to break your SQL statements into units so that in a given PL/SQL block, some units can be committed (saved to the database), others can be rolled back (undone), and so forth.
What is trigger in PL SQL?
A PL/SQL trigger is a named database object that encapsulates and defines a set of actions that are to be performed in response to an insert, update, or delete operation against a table. Triggers are created using the PL/SQL CREATE TRIGGER statement.
What is difference between commit and SAVEPOINT?
COMMIT − to save the changes. ROLLBACK − to roll back the changes. SAVEPOINT − creates points within the groups of transactions in which to ROLLBACK.
What are two main types of triggers?
There are two types of triggers.
- BEFORE trigger: – This trigger is called before the execution of the DML statement. …
- After Trigger: – this trigger is called after once DML statement is executed. …
- Combination of triggers: – We can have combination of row, statement, BEFORE and AFTER triggers.
Is commit a DDL command?
why commit is not required for DDL commands whereas it is compulsory for DML commands to save changes permanently to the database.
Are DDL commands Autocommit?
No. Only the DDL(Data Definition Language )statements like create,alter,drop,truncate are auto commit.
How do I ROLLBACK in PL SQL?
The ROLLBACK statement undoes all changes for the current session up to the savepoint specified by savepoint_name. If this clause is omitted, then all changes are undone. Optional. It is used to force the rollback of a transaction that may be corrupt or in doubt.
What is commit in PL SQL?
The COMMIT statement makes permanent any changes made to the database during the current transaction. A commit also makes the changes visible to other users. … The SQL COMMIT statement can be embedded as static SQL in PL/SQL. For syntax details on the SQL COMMIT statement, see the Oracle Database SQL Reference.
Can we use commit in exception block?
1 Answer. Yes it’s possible to use either COMMIT or ROLLBACK in an EXCEPTION block.