Contents
File-Based Approach
Database Approach
Definitions and Basic Terminology
DBMS
RDBMS
File-Based Approach
File-based approach is the preliminary approach to data storage. It is based on relatively simple data structures, such as the Indexed Sequential Access Method, and is usually implemented for a single application.
Files are generally created on an as needed basis to service the data needs of an application. The files are associated with an application.
A file-based data storage approach makes it difficult for other applications to access data not owned by their application. Because the physical storage characteristics of the same data may be different for different applications, therefore data owned by one application may be stored in a format not consistent with the retrieval capabilities of another application.
This causes inconsistency while updating data files across the organization. The primary reason it is that the File-based approaches to data storage are tied to applications rather than the entities/ objects to which the files refer. This problem is overcome by database approach.
Database Approach
Database approaches to data storage support the sharing of data across multiple applications with multiple users.
Databases are structured in a way that is meaningful to an organization.
The data are stored in such a way that they are independent of the programs used by the people for accessing the data.
The approach used in adding the new data, modifying and retrieving the existing data from the database is common and controlled one.
For example, if an organization maintains information on suppliers and the geographic areas they service, there would be a link in the database between the suppliers and geographic areas.
Databases reduce data redundancy. Hence a database is a collection of interrelated data stored together with controlled redundancy to serve one or more applications in an optimal way.
Definitions and Basic Terminology
Database Management System (DBMS)
A database management system (DBMS) is a general-purpose software system.
It is a collection of programs that enables users to define, create and maintain a database and provide controlled access to the data.
A database has the following properties:
- A database represents some aspects of real world. And changes in the real world are reflected in the database.
- A database is logically coherent collection of data with some inherent meaning.
- A database is built and implemented with data for a specific purpose. It has a group of users who can access, modify and update the database.
- DBMS is actually a tool used to perform any kind of operation on data in database. DBMS also provides protection and security to database. It maintains data consistency in case of multiple users.
Relational Database Management System (RDBMS)
- Edgar Codd introduced the relational database model. Many modern DBMS do not conform to the Codd’s definition of a RDBMS, but nonetheless they are still considered to be RDBMS.
- RDBMS data is structured in database tables, fields and records. Each RDBMS table consists of database table rows. Each database table row consists of one or more database table fields.
- RDBMS store the data into collection of tables, which might be related by common fields (database table columns). RDBMS also provide relational operators to manipulate the data stored into the database tables.
- Most RDBMS use SQL as database query language. Some examples of 5 popular DBMS are MySql, Oracle, Sybase, Microsoft Access and IBM DB2, UNIFORM and INFORMIX etc.
Database
A collection (or list) of information. A database is comprised of one or more lists (called tables) of data organized by columns, rows, and cells.
Tables
The view that displays the data base as a combinations of rows (records) and columns (fields). The cells contain the bits and pieces of data for each record in each field. The first row of a table is reserved for the field names.
Field Names
Identify the different categories in a database. The top row is reserved for field names. Examples of field names are First name, last name, address, city, state, zip, phone number.
Data
All of the records of information in a database including the field names. Data + Field Names = Records All Records = a Database.
Cells
The intersection of columns and rows that contain the data for each record.
Fields
It is the smallest unit of the data that has meaning to its users and is also called data item or data element. Name, Address and Telephone number are examples of fields. These are represented in the database by a value. Fields are the categories in a database. Fields are displayed in columns. For Example, in a database, the zip field contains all the zip codes from each of the records. These are the bits and pieces of data.
Records
A record is a collection of logically related fields and each field possess a fixed number of bytes and is of fixed data type. Alternatively, we can say a record is one complete set of fields and each field has some value. The complete information about a particular phone number in the database represents a record.
Files
A file is a collection of related records. Generally, all the records in a file are of same size and record type but it is not always true. The records in a file may be of fixed length or variable length depending upon the size of the records contained in a file. The telephone directory containing records about the different telephone holders is an example of file.
Other Tutorials
HTML Tutorials
Java Tutorials
RDBMS Tutorials
Other Popular Posts
HTML
Information System
Cloud Computing
Mobile Computing
E-Commerce
Computer
Java
Databse
Operating System