Skip to main content

Active Database


Oracle Freshers training , Cognizant - Calcutta

Active Database


An active Database is a database consisting of a set of triggers. These databases are very difficult to be maintained because of the complexity that arises in understanding the effect of these triggers. In such 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. In such situation, DBMS processes each of the trigger randomly. The execution of an action part of a trigger may either activate other triggers or the same trigger that Initialized this action. Such types of trigger that activates itself is called as ‘recursive trigger’. The DBMS executes such chains of trigger in some pre-defined manner but it effects the concept of understanding.

  

Features of Active Database:

  1. It possess all the concepts of a conventional database i.e. data modelling facilities, query language etc.
  2. It supports all the functions of a traditional database like data definition, data manipulation, storage management etc.
  3. It supports definition and management of ECA rules.
  4. It detects event occurrence.
  5. It must be able to evaluate conditions and to execute actions.
  6. It means that it has to implement rule execution.

Advantages :

  1. Enhances traditional database functionalities with powerful rule processing capabilities.
  2. Enable a uniform and centralized description of the business rules relevant to the information system.
  3. Avoids redundancy of checking and repair operations.
  4. Suitable platform for building large and efficient knowledge base and expert systems.

Comments

Post a Comment

Popular posts from this blog

PL / SQL practice programs

  PL / SQL  practice programs 1. Write a program to print the following format WELCOME TO PL/SQL PROGRAMMING   BEGIN   DBMS_OUTPUT.PUT_LINE('WELCOME   TO   PL/SQL   PROGRAMMING'); END; /   2. Write a program to print the numbers from 1 to 100   DECLARE N NUMBER(3):=1; V VARCHAR2(1000); BEGIN WHILE N <=1000 LOOP V:=V||''||N; N:=N+1; END LOOP; DBMS_OUTPUT.PUT_LINE(V); END; / 3. write a program to print the even numbers from 1 to 100 DECLARE N NUMBER(3):=0; BEGIN WHILE N <=100 LOOP N:=N+2; DBMS_OUTPUT.PUT_LINE(N); END LOOP; END; / 4. Write a program to print the odd numbers from 1 to 100 DECLARE N NUMBER(3):=1; BEGIN WHILE N <=100 LOOP N:=N+2; DBMS_OUTPUT.PUT_LINE(N); END LOOP; END; / 5. write a program for multiplication table DECLARE A NUMBER(2):=&A; B   NUMBER(2):=1; C ...
5 comments
Read more

RDBMS MINI PROJECT

  Capgemini class room training.   RDBMS MINI PROJECT ( SPRINT ) LIBRARY MANAGEMENT SYSTEM   Table of Contents Serial No. Topic Name Content Page No. 1.   Introduction 1.1 Setup checklist for mini project 3     1.2 Instructions 3 2.   Problem statement   2.1 Objective 4     2.2 Abstract of the project 4     2.3 Functional components of the project 4     2.4 Technology used 5 3.   Implementation in RDBMS LOT 3.1 Guidelines on the functionality to be built 6 4.   Evaluation 4.1 Evaluation 7   ...
1 comment
Read more
  COGNIZANT Freshers   ORACLE Training @  Pune 2014 What is Embedded SQL in DBMS?  When we talk about embedded SQL, it can be understood as small SQL queries put into high-level languages to get meaningful outputs. While embedding SQL queries into other high-level languages, we need to make sure that we have a working database connector on our system. By using the connectors we can easily run SQL queries on the existing databases in our RDBMS or we can even create new ones. Let us now dive deep into the embedded SQL concepts and learn more about it. What is Embedded SQL? As we have seen in our previous tutorials, SQL is known as the Structured Query Language. It is the language that we use to perform operations and transactions on the databases. When we talk about industry-level applications we need properly connected systems which could draw data from the database and present to the user. In such cases, the embedded SQL comes to our rescue. We embed SQL queries...
1 comment
Read more