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Question 6 :

What is an integrity constraint?

Answer :

Integrity constraint is a rule that restricts values to a column in a table.


Question 7 :

What is referential integrity constraint?

Answer :

Maintaining data integrity through a set of rules that restrict the values of one or more columns of the tables based on the values of primary key or unique key of the referenced table.


Question 8 :

What is the usage of SAVEPOINTS?

Answer :

SAVEPOINTS are used to subdivide a transaction into smaller parts. It enables rolling back part of a transaction. Maximum of five save points are allowed.


Question 9 :

What is ON DELETE CASCADE?

Answer :

When ON DELETE CASCADE is specified Oracle maintains referential integrity by automatically removing dependent foreign key values if a referenced primary or unique key value is removed.


Question 10 :

What are the data types allowed in a table?

Answer :

CHAR, VARCHAR2, NUMBER, DATE, RAW, LONG and LONG RAW.