A network databases are mainly used on a large digital computer. In the network model, entities are organized in a graph, in which some entities can be accessed through several paths. In this children are called members and parents are called occupier.
In this data is stored in the form of tables. The relationship between the data files is relational. Data in relational databases is stored in different access control tables, each having a key field that mainly identifies each row.
Database Management System
Components of a database
A database includes several components like object, tables, queries, and reports. An object can be anything in the real world.
Tables: These are the basic building blocks of any relational database. A table is a collection of rows and columns.
Field: It is a column of the table, which stores the specific information like customer address, and student address.
Record: It is a collection of data items of all the columns. It stores the information about one entity like a person and company. It is also known as tuples and the number of tuples in a relation is called as the cardinality of the relation.
Queries: A query refers to a question about the data and is used to retrieve the information.
Forms: These are used to view and edit the data.
Elements of Database: A database includes various elements like,
Entity: Entity is an object that exists in the real world and is represented by rectangles. It Includes the entire information of the data.
Examples: customer buy goods, in this customer and goods are the entities.
Entity set: It is a collection of similar entities, which can share the same properties.
Example: Student is an entity set of all student entities.
Attributes: These are the properties of the entity that can be represented in an elliptical shape. These can be represented by columns in a table.
Examples: ITEM entity properties like code, and prize.
Relationship: A relationship is a union among various entities. In this, entities are related to each other. It is represented in a diamond shape. The relationship can be divided as One to one, one to many, and many to many.
E-R Diagram: It is the representation of entities and relationship between them.
Architecture of database
Data Abstraction: It hides certain details about the data. This is also known as data model, which is a collection of conceptual tools for describing the data and that is divided into three levels.
Advantages of DBMS
Disadvantage of DBMS
Uses of DBMS
2. Database is collection of _____.
3. Which of the following is considered as DBMS?
4. Arrange according to the size__________.
5. The DBMS acts as an interface between what two components of an enterprise-class database system?
6. SQL stands for ________.
7. The following are functions of a DBMS except ________.
8. DBMS help to achieve _______.
9. A set of related files is called a___.
10. Which of the following is not a logical data-base structure?
11. What is the language used by the most of the DBMS for helping their uses to access the data?
12. Periodically adding, changing and deleting file records is called file ________.
13. Which of the following hardware components is the most important to the operation of a database management system?
14. In a _____ parent record type can be linked to one or more “child” record types, but a child record type can have only one parent.
15. The logical data structure with a one-to-many relationship is a ______.
16. A number of related records that are treated as a unit is called__________.
17. SQL is ________.
18. SQL can be used to_______.
19. Which of the following option is used retrieval of data.
20. ____________ is a classical approach to database design ?