VIII A Data Base Concepts
A database management system (DBMS) is the software that allows a computer to perform database functions of storing, retrieving, adding, deleting and modifying data.
Relational database management systems (RDBMS) implement the relational model of tables and relationships.
Database
Data: is the required particular piece of information which we need.
The information in the database is stored in records.
Records: The records are information held in one row.
Field: Individual pieces of information is called as field
Example:
Let us take an example of list of all students in our school
Data: Information about one particular student or class
Record: Each line of information stored in the data base like information of each student
Field: Individual piece of information like Name, Admission number, Class, Register Number
Where do we use databases?
We use databases in daily bases in our daily activities.
E.g.: 1. List of our friends 2. List of all the students in our class 3. List of all students and their details 4. The school library
Databases are classified bases: 1. On the number of rows of information that can be held by it. 2. Ability to connect to different databases.(RDBMS) 3. Speed at which data can be retrieved 4. The method in which data is stored 5. Licensing method
Different Data Bases
1. 2. dBase III – Command line data base worked on DOS no RDBMS supported small and medium size database sizes up to 75000 records. Built-in frontend, reporting, development support 3. dBase IV & FoxPro – Command Line database worked on DOS and Networks with basic RDBMS supported Small and Medium database upto 1500000 records with many users accessing the database at the same time. Built-in frontend, reporting, development support. Supports Multiple databases in one project 4. db2 - Command Line database works on Unix