Accountancy Notes for Chapter 15 Database Management System Class 11 - FREE PDF Download
FAQs on Database Management System Class 11 Accountancy Chapter 15 CBSE Notes - 2025-26
1. What are the core concepts to summarise for the Class 11 chapter on Database Management Systems?
For a quick revision of this chapter, focus on these key concepts: A database is an organised collection of structured data. A Database Management System (DBMS) is the software used to create, manage, and access this database. The primary goal is to store and retrieve data efficiently and securely. Key components to remember are the data itself, the hardware, the software (DBMS), and the users.
2. What are the main advantages of using a DBMS, for a quick recap?
Revising the advantages of a DBMS is crucial. The main benefits over traditional file systems include:
Reduced Data Redundancy: DBMS minimises the duplication of data across different files.
Improved Data Consistency: By reducing redundancy, it ensures that all instances of data remain consistent.
Enhanced Data Security: It allows for better control over user access and permissions, protecting sensitive data.
Data Integrity: Enforces rules to ensure that the data stored is accurate and reliable.
Easy Data Sharing: Authorised users can access and share data concurrently.
3. How are Primary Keys, Candidate Keys, and Foreign Keys different in a database?
Understanding the difference between keys is a fundamental concept. A Candidate Key is any column or set of columns that can uniquely identify a row (or tuple) in a table. A table can have multiple Candidate Keys. From these, one is selected to be the Primary Key, which is the main identifier for the table and cannot have NULL values. Any Candidate Key that is not chosen as the Primary Key is called an Alternate Key. A Foreign Key is a key used to link two tables together; it is a field in one table that refers to the Primary Key in another table.
4. What is the basic structure of the Relational Data Model for revision?
The Relational Data Model organises data into tables, known as relations. For a quick concept map, remember these terms:
Relation: A table with rows and columns.
Tuple: A single row in a table, representing one complete record.
Attribute: A column in a table, representing a property of the record.
Domain: The set of permissible values for an attribute.
Degree: The total number of attributes (columns) in a relation.
Cardinality: The total number of tuples (rows) in a relation.
5. Why is the concept of data independence important in a DBMS?
Data independence is a crucial advantage of a DBMS because it separates the database schema from the application programs that use the data. There are two types: Physical data independence allows changes to the physical storage structure (e.g., changing storage devices) without affecting the application logic. Logical data independence allows changes to the logical schema (e.g., adding a new column) without needing to rewrite existing application programs. This separation makes database maintenance and upgrades significantly easier and more efficient.
6. What is a quick summary of essential SQL commands from the Class 11 syllabus?
For revision, remember that SQL commands are categorised based on their function. The two main categories for Class 11 are:
DDL (Data Definition Language): Used to define and manage the database structure. Key commands include CREATE TABLE (to make a new table), ALTER TABLE (to modify a table's structure), and DROP TABLE (to delete a table).
DML (Data Manipulation Language): Used to manage the data within the tables. Key commands are INSERT (to add new rows), UPDATE (to modify existing rows), DELETE (to remove rows), and SELECT (to retrieve data).
7. How do DDL and DML commands work together in practice?
Think of it as a two-step process. First, you use DDL commands like `CREATE TABLE` to build the 'container' or structure of your database. This sets up the blueprint, defining the table name, columns, and data types. Once the structure is in place, you use DML commands to work with the data inside that container. For example, you use `INSERT` to populate the table with records, `SELECT` to view them, and `UPDATE` to modify them. DDL builds the house, and DML furnishes and lives in it.
8. What is the role of MySQL in the Class 11 DBMS chapter?
In the context of the Class 11 syllabus for the 2025-26 session, MySQL is presented as a practical example of a Relational Database Management System (RDBMS). While the chapter teaches the theoretical concepts of databases and the syntax of SQL, MySQL is the actual open-source software that students often use to execute SQL commands, create tables, and manage data. It serves as the tool to apply the theoretical knowledge learned in the chapter.











