RDBMS stands for Relational Database Management System. It is a system that is used by software to store, manage, query, or retrieve data from the database in which data is stored in the form of tables and one table might be connected with many other tables using primary and foreign key relations. RDBMS provides us the interface between software and database to manage and perform the required operations on the database. Before starting with RDBMS concepts, it is important to understand a few important terms.
What is Information System?
Data with its meaning is referred to as information, where the data means raw fact. In specific, an information system is an organized collection of hardware, software, supplies, and procedures and people who store, process and provide access to information.
What is File Based System?
When information is stored in flat files, which are maintained by the file system under the operating system control. Application programs go through the file system in order to access these flat files. Records consist of various fields, which are delimited by a space, comma, pipe, or any special character, etc.
Maintaining records in a File based system is great and we are able to free up all that space by moving all the data on the computer.(alert-success)
There are many disadvantages of using the traditional file-based system like:
- The application develops in an ad-hoc manner.
- Data redundancy, because data can be duplicated in two or more files.
- Data isolation, which means all the related data are scattered in various files having a different file format, and hence, writing a new application becomes difficult in retrieving data.
- In File Based System it is difficult to produce reports across sales, product, and customer data because they are maintained on a separate file system. (alert-error)
What is Database?
A database is a shared collection of logically related data and the description of this data, designed to meet the needs of an organization.
Advantages of Database Approach:
- Centralization of Information Management.
- Data is shared by different groups of users and application programs.
- Representation of complex relationship between data.
- Integrity Constraint handling.
- Advanced facility for backup and recovery.
What is Database Management System?
Database Management System (DBMS) is software that helps in defining, creating, and maintaining the database that provides controlled access to the database.
Advantages of Database Management System:
- Shared file system.
- Enforcement of Security.
- Enforcement of development and maintaining standards.
- Reduction of redundancy.
- Avoidance of inconsistency across files.
- Maintenance of integrity.
- Data Independence.
- Authentication- Whether the right user has the right to access the database.
- Authorization- Whether the right user has the right to access the database.
Data Model.
- Hierarchical models refer to storing the data by a tree structure. This model handles only parent-child relationships which are one-to-many relationships. It is not easy to perform, insert, update and delete operations in this model.
- In-Network models data is represented as a graph which Nodes and Edges. It addresses many to many relationships. It has a very complex design.
- Relational Data Model is a widely used data model. The data is stored in the form of tables with rows and columns and it is easy to use because there is no usage of a pointer. Data access is faster than other models. This data model uses the relational algebra concept.
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