Course ID : CS540_C Student ID : 14072 Student Name: Lavanya Soma Homework # : 08 1) Data integrity means that data in a database adheres to business rules. There are three primary ways in which data integrity can be maintained: Application Code Database triggers Declarative integrity constraints 2) An integrity constraint can be enabled (ENABLE) or disabled (DISABLE). If a constraint is enabled, data is checked as it is entered or updated in the database. If a constraint is disabled, then data that does not confirm can be entered into the database. An integrity constraint can be one of the following states: DISABLE NOVALIDATE DISABLE VALIDATE ENABLE NOVALIDATE
ENABLE VALIDATE 3) Constraint checking: You can defer checking constraints for validity until the end of the transaction. Nondeferred constraints are enforced at the end of every DML statement. A constraint violation causes the statement to be rolled back. If a constraint causes an action such as cascade, the action is taken as part of the statement that caused it. A constraint that is
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- Spring '16
- data integrity, password history