The document discusses database management systems and distributed databases. It covers the problems with flat file data storage, how databases address these issues, database design concepts like normalization, and the advantages and challenges of distributed database systems. Distributed databases can be centralized, partitioned, or replicated across multiple sites to improve performance, but maintaining data consistency is challenging and requires concurrency control methods.

1. Chapter 9 Database Management Systems

4. Flat-File Environment Program 1 Program 2 Program 3 A,B,C X,B,Y L,B,M User 2 Transactions User 1 Transactions User 3 Transactions Data

6. Program 1 Program 2 Program 3 User 2 Transactions User 1 Transactions User 3 Transactions Database D B M S A, B, C, X, Y, L, M Database Approach

9. Elements of the Database Approach System Development Process Database Administrator U S E R S DBMS Host Operating System Physical Database User Programs User Programs User Programs Applications Data Definition Language Data Manipulation Language Query Language User Queries Transactions Transactions Transactions System Requests

15. Functions of the DBA

18. PROJECT - filtering out columns, such as the green Z3 JOIN RESTRICT - filtering out rows, such as the yellow X1 X1 X2 X2 X3 X3 Y1 Y1 Y1 Y1 Y1 Y2 Y2 Y2 Y3 Z1 Z1 Z2 Z2 Z1

20. Crow’s Feet Cardinalities (1:0,1) (1:1) (1:0,M) (1:M) (M:M)

25. Steps in Normalization Table with repeating groups First normal form 1NF Second normal form 2NF Third normal form 3NF Higher normal forms Remove repeating groups Remove partial dependencies Remove transitive dependencies Remove remaining anomalies

38. The Deadlock Phenomenon A,B E, F C,D Locked A, waiting for C Locked C, waiting for E Locked E, waiting for A