What are the uses of active database? Discuss active database with example.

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 The uses of an active database are as follows:-

  • It possesses all the concepts of a conventional database i.e. data modeling facilities, query language, multi-user access, recovery, etc.
  • It supports all the functions of a traditional database, including data definition, data manipulation, storage management, transaction management, concurrency control, and crash recovery.
  • An active database supports the definition and management of ECA rules.
  • An active database must detect event occurrences. An active database must be able to evaluate conditions and execute actions.
  • An active database includes an event-driven architecture (often in the form of ECA rules) An active database must be able to evaluate conditions and execute actions. This requirement means that it has to implement rule execution. 


Active Database

A trigger is a procedure that is automatically invoked by the DBMS in response to changes to the database and is specified by the database administrator (DBA).A database with a set of associated triggers is generally called an active database. These databases are very difficult to be maintained because of the complexity that arises in understanding the effect of these triggers. In such a database, DBMS initially verifies whether the particular trigger specified in the statement that modifies the database) is activated or not, prior to executing the statement. If the trigger is active then DBMS executes the condition part and then executes the action part only if the specified condition is evaluated to true. It is possible to activate more than one trigger within a single statement.









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