Database Management System Class 10 Notes by J.D Sir
What is Database?
Ans : An organised group of data that is kept and accessible electronically is referred to as a database. It is a digital repository that enables the effective management, storage, and retrieval of both organised and unorganised data. Information like client records, financial data, inventory listings, and much more can be stored in databases. Example of database are – Microsoft Access, OpenOffice Base, Oracle, MySQL and PostgreSQL etc.
What is a Database Management System?
Ans: Data is stored, retrieved, and analyzed using software called database management systems (DBMS). Users can create, read, update, and remove data in databases using a Database Management System, which acts as an interface between them and the databases. Example of database Management System are – Microsoft Access, OpenOffice Base, Oracle, MySQL and PostgreSQL etc.
Data can be organized into two types:
- Flat File: Data is stored in a single table. Usually suitable for less amount of data. basically for small-scale organization where data does not need to be strucutred in a complex way. Example of database software are Microsoft Excel or Google Sheets.
- Relational: Data is stored in multiple tables and the tables are linked using a common field. Relational is suitable for medium to large amount of data. Example of database software are MySQL, Microsoft SQL Server, and Oracle Database..
What is Database Server?
Database servers are dedicated computers that are designed to store data and provide database services to other computers. We use a database to store, organize, manage and retrieve data efficiently and effectively. The database servers run only database and database related software.
Advantages of Database
Reduces Data Redundancy
Sharing of Data
Data Integrity
Data Security
Privacy
Backup and Recovery
Data Consistency
Data redundancy means when same data is stored more than one places, which increased complexity and wasted of storage space, so, database helps to reduce data redundacy.
A database allows its users to exchange data among themselves. The data can only be shared with users who have received the appropriate degrees of authorization because there are different levels of access to the data.
Data integrity refers to the accuracy and consistency of data stored in a database management system (DBMS). Database ensures that the data is reliable and can be trusted for decision making and other critical business processes.
A database’s concept of data security is important. The database should only be accessible to authorised users, whose identities must be verified using a username and password.
The privacy rule in a database ensures that only authorized users can access the database and view data according to the specific privacy constraints. To maintain data security, access levels are set in the database so that a user can only view data that they are not allowed to modify if the permission is not given.
For example, in social networking sites, different accounts have different access constraints, and users are only allowed to view the other account data that is permitted for their specific account.
Database Management System automaticlly take backup and recovery processes to ensure the protection and availability of data. This means that the DBMS automatically creates and manages backups of the database at regular intervals, and also provides tools to recover data in the event of a failure or data loss.
Data consistency refers to the accuracy and reliability of data stored in a database or other data storage system. It means that the data is consistent and valid across all instances where it is stored or accessed.
For example, if a customer’s name and address are stored in multiple tables within a database, the data must be consistent across all table.
Database Management System Class 10 Notes by J.D Sir
Features of Database
There are some key features of a database:
- One or more tables can be added in the database.
- Decreased storage costs and space requirements
- Users can use query languages in a database.
- Multiple users can access the data from the database .
- Unique keys aid in preventing errors caused by human or technological mishaps.
Primary Key, Composite Primary Key and Foreign Key in a Database
In the RDBMS data can be integrated using keys. These are Primary Key, Composite Primary Key, and Foreign Key, Key are used to make the relationship between the tables.
Primary Key
This unique field is called the Primary Key (PK). primary key is a field or a set of fields that uniquely identify each record in a table. A primary key must be unique and cannot contain null values.Composite Primary Key
A composite primary key is a primary key that consists of two or more fields that together uniquely identify each record in a table.Foreign Key
A composite primary key is a primary key that consists of two or more fields that together uniquely identify each record in a table.
What is RDBMS?
A database management system that is based on the relational model is called an RDBMS (Relation Database Management System). Tables are used to organise data in relational databases. A relational database management system (RDBMS) is used to store, manage, query, and retrieve data.
Database Objects
Tables:
Columns or Fields or Attributes:
Rows or Records or Tuples:
Data is arranged into rows and columns in a table, which is a type of data structure. It can be applied to both the storage and presentation of structured data.
Data is arranged vertically from top to bottom in columns. Each row of the table has one column, which is a collection of data values of a specific basic type. The structure by which the rows are put together is provided by the columns.
A row, also known as a Record or Tuple, in a table represents a single data item. A database table can be represented graphically as being made up of rows and columns, or fields. Every row in a table has the same structure and represents a group of connected data.
Database Management System Class 10 Notes by J.D Sir
Difference between DBMS and RDBMS
| Aspect | DBMS | RDBMS |
|---|---|---|
| Data structure | Data is stored in various formats such as flat files or hierarchical structures. | Data is stored in tables that are related to each other using a relational model. |
| Data integrity | DBMS systems may or may not enforce strict data integrity rules. | RDBMS systems enforce strict data integrity rules that ensure data consistency and accuracy. |
| Data normalization | DBMS systems may or may not follow normalization rules. | RDBMS systems follow normalization rules to minimize data redundancy and improve data integrity. |
| Query language | Typically, DBMS systems use proprietary query languages. | RDBMS systems use standard query language like SQL. |
| Scalability | DBMS systems may not be scalable to handle large amounts of data. | RDBMS systems are highly scalable to handle large amounts of data. |
| Cost | DBMS systems are generally less expensive than RDBMS systems. | RDBMS systems are generally more expensive than DBMS systems. |