Introduction to DBMS
A Database Management System (DBMS) is software that enables the creation, management, and use of databases. Much like an operating system manages hardware, a DBMS manages data resources, allowing multiple users to store, retrieve, and secure large volumes of structured and unstructured data efficiently
Components of a DBMS [5]
A DBMS relies on five key components to function:
* Database Engine: Handles the storage, retrieval, and processing of data.
* Query Processor: Interprets and executes SQL commands.
* Transaction Manager: Ensures transactions maintain data integrity (see ACID below).
* Storage Manager: Allocates physical disk space and manages efficient data retrieval.
* Security Manager: Handles authentication and access controls.
Database Characteristics (The ACID Model) [4]
The ACID model defines four critical properties required to ensure database transactions remain reliable and consistent, even during failures.
* Atomicity: Transactions are treated as a single unit. Either all operations within a transaction succeed, or none do. If one part fails (e.g., deducting money from one account but failing to add it to another), the entire transaction is rolled back to the previous state,.
* Consistency: The database must transition from one valid state to another. It ensures that transactions follow all defined rules and integrity constraints (e.g., a bank account balance cannot be negative).
* Isolation: Multiple transactions occurring simultaneously must not interfere with one another. Each transaction operates independently until it is fully completed.
* Durability: Once a transaction is committed, the changes are permanent. Even in the event of a system crash or power failure, the data remains saved
