Describe Data Dictionary. Wire any four advantages.

-

 Solution:-

Data dictionary:-

1. Data dictionaries are lists of all of the names used in the system models. Descriptions of the entities, relationships and attributes are also included.

 2. Data dictionary as the central database for the description of all data objects. 

3. Once entries in the dictionary are defined, entity-relationship diagrams can be created and object hierarchies can be developed. Many CASE workbenches support data dictionaries.

Advantages:

1. Support name management

2. Avoid duplication

3. Store of organizational knowledge linking analysis, design and implementation

4. It is a valuable reference in any organization because it provides documentation.

5. It improves the communication between system analyst and user by establishing consistent definitions of various items terms and procedures.

6. It is a good tool for manage operators and other members of the development team

Comments

Post a Comment

Popular posts from this blog

State the functions of Hub, Repeater, Bridge and Router.

-
  1)Hub : Hub connects all nodes in star topology. Hub is broadcasting device. It sends packets to all nodes in the network. It works at Physical Layer of OSI model. 2) Repeater : Repeaters are used to take the distorted, weak and corrupt input signal and regenerate this signal at its output. It ensures that the signals are not distorted or weak before it reaches the destination. It increases the signal strength. 3)Bridge : A bridge device filters data traffic at a network boundary. Bridges reduces the amount of traffic on a LAN by dividing it into two segments. It inspects incoming traffic and decides whether to forward or discard it. It sends packets between two networks of same type. 4)Router : Router chooses the best path for packet forwarding. Router read complex network address in packet. It works at Network Layer of OSI model Efficiently direct packets from one network to another, reducing excessive traffic. Join neighbouring or distant network Connect dissimilar networks. P...
Read more

Describe the OSI model with neat diagram.

-
Image
  Solution:- OSI model (open system interconnection) model was developed by ISO (international standard organization) Function of OSI model: i. It provides way to understand how internetwork operates.  ii. It gives guideline for creating network standard. OSI model has 7 layers as shown in the figure.  OSI model has following 7 layers as Physical layer, data link layer, Network layer, Transport layer, session layer, presentation layer, application layer.  1. Physical layer: 1. It co-ordinates the functions required to transmit bit stream over physical medium. 2. It deals with mechanical and electrical specifications of interface and transmission medium. Functions of physical layer are: Physical characteristics of interfaces and media.  Representation of bits: Data rate (transmission rate).  Synchronization of bits.  Line configuration: Point to point or multipoint configuration should be used.  2. Data link layer: 1. It is responsible for transmit...
Read more

Explain Database languages.

-
Data Definition Language The language is used to create database, tables, alter them, etc. With this, you can also rename the database, or drop them. It specifies the database schema. The DDL statements include − CREATE :  Create new database, table, etc. ALTER : Alter existing database, table, etc. DROP : Drop the database RENAME : Set a new name for the table. Data Manipulation Language The language used to manipulate the database like inserting data, updating table, retrieving record  from a table, etc. is known as Data Manipulation Language − SELECT : Retrieve data from the database INSERT : Insert data UPDATE :  Update data DELETE : Delete all records Data Control Language Grant privilege to a user using the GRANT statement. In the same way, revoke the privilege using the REVOKE statement. Both of these statements come under the Data Control Language (DCL). − GRANT : Give privilege to access the database. REVOKE:  Take back the privilege to access the database. ...
Read more