Gayathri

                                                     1.1 Purpose of Database System A database system is a combination of data , software , and rules that lets people store, manage, and retrieve information efficiently. 1. What makes up a database system? Database – the organized collection of data (tables, records, fields) DBMS (Database Management System) – software that manages the data Examples: MySQL, PostgreSQL, Oracle, MongoDB Users & applications – people or programs that access the data Hardware – servers, storage, and networks Procedures – rules for using and maintaining the data 2. What does a DBMS do? Stores large amounts of data safely Allows fast searching and updating Controls access (security) Prevents data loss (backups & recovery) Handles multiple users at the same time 3. Types of databas...

UNIT I RELATIONAL DATABASES  Purpose of Database System – Views of data – Data Models – Database System Architecture – Introduction to relational databases – Relational Model – Keys – Relational Algebra – SQL fundamentals – Advanced SQL features – Embedded SQL– Dynamic SQL UNIT II DATABASE DESIGN Entity-Relationship model – E-R Diagrams – Enhanced-ER Model – ER-to-Relational Mapping – Functional Dependencies – Non-loss Decomposition – First, Second, Third Normal Forms, Dependency Preservation – Boyce/Codd Normal Form – Multi-valued Dependencies and Fourth Normal Form – Join Dependencies and Fifth Normal Form UNIT III TRANSACTIONS Transaction Concepts – ACID Properties – Schedules – Serializability – Transaction support in SQL – Need for Concurrency – Concurrency control – Two Phase Locking - Timestamp – Multiversion – Validation and Snapshot isolation – Multiple Granularity locking – Deadlock Handling – Recovery Concepts – Recovery based on deferred and immed...