MySQL Introduction And File Oriented System
MySQL, pronounced either “My S-Q-L” or “My Sequel,” is an open-source relational database management system, And it was developed by Michael Widenius and David Axmark in 1994. MySQL name is a combination of “My”, the name of co-founder Michael Widenius’s daughter,and “SQL”, the abbreviation for Structured Query Language.It was Written in C, C++.
What Is MYSQL?
MySQL is a database computer language designed for the retrieve and management of data in relational dataBase,Also Lots of databases support SQL as the programming language and the most popular one, particularly when it comes to website software, is MySQL. And below are the following points to become MYSQL, SO popular:
- MySQL is often used as a free back-end database for many web and other open source applications.
- MySQL is a relational database management system.
- Easy to use with basic SQL Concepts
- MySQL is fast reliable and flexible
- Secure by encrypting passwords.
The Evolution Of Database Systems
The Evolution of Database systems are as follows:
- File Management System
- Hierarchical database System
- Network Database System
- Relational Database System
1. File Management System:
The file management system also called as FMS in short is one in which all data is stored on a single large file. The main disadvantage in this system is searching a record or data takes a long time. This lead to the introduction of the concept, of indexing in this system. Then also the FMS system had lot of drawbacks to name a few like updating or modifications to the data cannot be handled easily, sorting the records took long time and so on. All these drawbacks led to the introduction of the Hierarchical Database System.
2. Hierarchical Database System:
The previous system FMS drawback of accessing records and sorting records which took a long time was removed in this by the introduction of parent-child relationship between records in database.
3. Network Database System:
In this the main concept of many-many relationships got introduced. But this also followed the same technology of pointers to define relationships with a difference in this made in the introduction if grouping of data items as sets.
4. Relational Database System:
In order to overcome all the drawbacks of the previous systems, the Relational Database System got introduced in which data get organized as tables and each record forms a row with many fields or attributes in it. Relationships between tables are also formed in this system.
Basic Concept Of Database Systems
Below are the basic concept of database systems.
Data is a raw facts and the word “raw” indicates that they have not been processed.For Example : 42 is a Data
The processed data is called as information.For Example: Marks: 42; then it becomes information
Knowledge based on the practical use of information. Knowledge necessarily includes a personal experience.
The process of changing the data /raw facts into meaningful information is called as data/information processing.
DIFFERENCE BETWEEN DATA AND INFORMATION:
|Meaningless/Raw facts||Processed data|
|It is in unorganized form||It is in organized form|
|Data doesn’t help in decision||Information helps in decision making process|
FILE ORIENTED APPROACH:
In earlier, Business computer systems were used to process records and produce information. They were generally faster and more accurate than manual systems. These systems stored groups of records in separate files, and so they were known as file processing systems.
- File system is a collection of data.
- File system gives the details of the data representation and Storage of data.
- In File system storing and fatching of data cannot be done efficiently.
- File system doesn’t provide crash recovery methods.
Eg. While we are entering some data into the file and if System crashes then records of the file is lost.
- File system is very difficult for protecting a file.
DISADVANTAGES OF FILE-ORIENTED SYSTEM:
1. Data Redundancy and Inconsistency:
Since files and application programs are created by different programmers over a long period of time, the files are likely to be having different formats and the programs may be written in several programming languages. Moreover, the same piece of information may be duplicated in several places. This redundancy leads to higher storage and access cost. In addition, it may lead to data inconsistency.
2. Data Isolation:
Since data is scattered in various files, and files may be in different formats, it is difficult to write new application programs to retrieve the appropriate data.
3. Difficulty in Accessing Data:
The conventional file processing environments do not allow needed data to be retrieved in a convenient and efficient manner. Better data retrieval system must be developed for
4. Concurrent Access Anomalies:
In order to improve the overall performance of the system and obtain a faster response time, many systems allow multiple users to update the data simultaneously. In such an environment, interaction of concurrent updates may result in inconsistent data.
5. Security Problems:
Not every user of the database system should be able to access all the data. For example, in banking system, payroll personnel need only that part of the database that has information about various bank employees. They do not need access to information about customer accounts. It is difficult to enforce such security constraints.
6. Integrity Problems:
The data values stored in the database must satisfy certain types of consistency constraints. For example, the balance of a bank account may never fall below a prescribed amount.