Database Systems: A Practical Approach to Design, Implementation and Management 4th Edition - How to Access the Solutions Manual
Database Systems By Thomas Connolly 4th Edition Solutions
If you are looking for a comprehensive and practical guide to designing, implementing, and managing database systems, then you should check out Database Systems: A Practical Approach to Design, Implementation, and Management by Thomas Connolly and Carolyn Begg. This book is one of the best-selling textbooks on database systems that covers both theoretical and practical aspects of database design, development, administration, and application. It also provides solutions to selected exercises that help you test your understanding and skills.
Database Systems By Thomas Connolly 4th Edition Solutions
In this article, we will give you an overview of what this book is about and why it is important. We will also show you how to use the book and its solutions effectively. Then, we will go through some of the key topics that this book covers in detail. Finally, we will conclude with some recommendations and tips for using the book and its solutions. We will also answer some frequently asked questions that you might have about this book.
Introduction
Database Systems: A Practical Approach to Design, Implementation, and Management by Thomas Connolly and Carolyn Begg is a textbook that aims to provide a clear introduction to database design, implementation, and management issues. It also offers an extensive treatment of database languages and standards, such as SQL, QBE, OQL, XML. The book covers both traditional topics such as relational databases, normalization, entity-relationship modeling, transaction processing, etc., as well as emerging topics such as web databases, data warehousing, data mining, object-oriented databases, XML etc.
The book is divided into six parts:
Part I: Background introduces the basic concepts of databases, data models, database users, database architecture etc.
Part II: Design Methodology explains how to design database systems using a three-phase methodology: conceptual design (using entity-relationship modeling), logical design (using relational modeling), and physical design (using implementation techniques).
Part III: Relational Databases covers the theory and practice of relational databases, including relational algebra, relational calculus, SQL, QBE, integrity constraints, normalization, etc.
Part IV: Advanced Database Topics explores some of the advanced topics in database systems, such as object-oriented databases, web databases, XML, data warehousing, data mining etc.
Part V: Database Development discusses how to develop database applications using various tools and techniques, such as database design tools, CASE tools, application generators, report writers, etc.
Part VI: Database Management covers the issues and challenges of database management, such as data quality, security, integrity, concurrency, recovery, performance etc.
The book also provides solutions to selected exercises at the end of each chapter. These solutions help you check your understanding and reinforce your learning. The solutions are also available online at http://infolab.stanford.edu/ullman/dscbsols/sols.html.
To use the book and its solutions effectively, you should follow these steps:
Read the chapter carefully and try to understand the concepts and examples.
Do the exercises at the end of the chapter and compare your answers with the solutions.
If you have any doubts or questions, refer to the book or other sources for clarification.
Review the chapter summary and key terms to reinforce your learning.
Database Design Methodology
One of the most important topics that this book covers is database design methodology. Database design is the process of creating a conceptual model of the data and its relationships that will be stored in a database. Database design is important because it affects the quality, performance, usability, and maintainability of the database system. A good database design should meet the following criteria:
It should reflect the real-world situation that the database is intended to model.
It should be easy to understand and modify by users and developers.
It should avoid data redundancy and inconsistency.
It should ensure data integrity and security.
It should support efficient data access and manipulation.
The book introduces a three-phase database design methodology that helps you achieve a good database design. The three phases are:
Conceptual Design
In this phase, you analyze the requirements of the database system and create a high-level model of the data and its relationships using an entity-relationship (ER) diagram. An ER diagram is a graphical representation of entities (things or objects of interest), attributes (properties or characteristics of entities), and relationships (associations or interactions between entities). An ER diagram helps you capture the meaning and structure of the data in a clear and concise way. For example, here is an ER diagram for a university database that stores information about students, courses, and instructors:
+----------------+ +----------------+ +----------------+ Student Course Instructor +----------------+ +----------------+ +----------------+ student_id <--+--+ course_id <--+--+ instructor_id student_name course_name instructor_name student_email course_credits instructor_email student_major --+ +----------------+ +----------------+ +----------------+ +----------------+ Enrolls +----------------+ grade +----------------+
Logical Design
In this phase, you map the conceptual model to a logical model that is compatible with the chosen database management system (DBMS). A DBMS is a software system that provides facilities for creating, manipulating, and managing databases. There are different types of DBMSs, such as relational DBMSs (RDBMSs), object-oriented DBMSs (OODBMSs), XML DBMSs etc. The most widely used type of DBMS is RDBMS, which organizes data into tables (or relations) consisting of rows (or tuples) and columns (or attributes). In this phase, you convert the ER diagram into a set of tables that follow the rules of relational model. For example, here is a possible logical design for the university database using RDBMS:
+---------------+ +---------------+ +---------------+ Student Course Instructor +---------------+ +--------------- student_id <--+--+ course_id <--+--+ instructor_id student_name course_name instructor_name student_email course_credits instructor_email student_major +---------------+ +---------------+ +---------------+
To convert the ER diagram into a set of tables, you need to follow some rules of relational model, such as:
Each entity type becomes a table.
Each attribute becomes a column.
Each relationship becomes a foreign key.
Each table must have a primary key.
Each table must be in a normal form.
Physical Design
In this phase, you optimize the logical model for the specific DBMS and hardware platform that you are using. You consider various factors such as storage space, access time, memory usage, disk layout, indexing, partitioning, etc. You also implement the integrity constraints, authorization rules, and transaction boundaries that were defined in the previous phases. For example, here are some possible physical design decisions for the university database using RDBMS:
Use B-tree indexes for the primary keys and foreign keys.
Use hash partitioning for the Student table based on student_major.
Use compression for the Course table to reduce storage space.
Use triggers and stored procedures to enforce integrity constraints and authorization rules.
Database Languages and Standards
Another important topic that this book covers is database languages and standards. Database languages are formal languages that allow you to define, manipulate, and query data in a database. Database standards are specifications that define how database languages should be implemented and used. The book covers four main database languages and standards: SQL, QBE, OQL, and XML.
SQL
SQL (Structured Query Language) is the most widely used database language in the world. It is a declarative language that allows you to specify what you want to do with data without specifying how to do it. SQL has three main components: DDL (Data Definition Language), DML (Data Manipulation Language), and DQL (Data Query Language).
DDL allows you to define the structure and schema of the database, such as creating tables, views, indexes, etc.
DML allows you to manipulate the data in the database, such as inserting, updating, deleting, etc.
DQL allows you to query the data in the database, such as selecting, joining, grouping, etc.
SQL is a standard language that is defined by various organizations such as ANSI (American National Standards Institute) and ISO (International Organization for Standardization). However, different DBMS vendors may implement different versions or extensions of SQL that are not fully compatible with each other. For example, Oracle SQL, MySQL SQL, SQL Server SQL etc.
QBE
QBE (Query By Example) is a graphical database language that allows you to query data by providing an example of what you want. QBE uses a tabular format that resembles a spreadsheet or a form. You can enter values or conditions in the cells of the table to specify what data you want to retrieve or modify. QBE is an intuitive and user-friendly language that does not require any knowledge of syntax or semantics. However, QBE is not as expressive or powerful as SQL and may not support some complex queries or operations. QBE is mainly used as a front-end tool for generating SQL queries behind the scenes.
OQL
OQL (Object Query Language) is a database language that allows you to query data in object-oriented databases. Object-oriented databases are databases that store data as objects rather than tables. Objects are entities that have attributes (data) and methods (behavior). Objects can also have complex data types and relationships such as inheritance, aggregation, composition etc. OQL is an extension of SQL that supports object-oriented features such as classes, methods, constructors, inheritance etc. OQL is a standard language that is defined by ODMG (Object Data Management Group). However, OQL is not widely adopted or implemented by many DBMS vendors.
XML
XML (Extensible Markup Language) is a database language that allows you to represent and exchange data on the web. XML is a semi-structured language that uses tags and attributes to describe the structure and meaning of data. XML is a flexible and extensible language that can be used to model any kind of data. XML is not a standard language but a meta-language that can be used to define other languages such as HTML, XHTML, RSS, SOAP, etc. XML is mainly used as a data interchange format rather than a data storage format. XML can be queried and manipulated by various languages and tools such as XQuery, XPath, XSLT, DOM, SAX etc.
Database Implementation and Management
The book also covers the practical aspects of database implementation and management. Database implementation is the process of creating and maintaining the physical database according to the logical design. Database management is the process of ensuring the quality, security, integrity, concurrency, recovery, and performance of the database system. The book discusses some of the main issues and challenges of database implementation and management, such as:
Data Quality
Data quality is the degree to which the data in the database is accurate, complete, consistent, timely, and relevant. Data quality is important because it affects the reliability and usability of the database system. Poor data quality can lead to errors, inefficiencies, losses, or even disasters. Data quality can be improved by various techniques such as data cleansing, data validation, data auditing, data profiling etc.
Data Security
Data security is the degree to which the data in the database is protected from unauthorized access, modification, or disclosure. Data security is important because it affects the confidentiality and integrity of the database system. Data security can be compromised by various threats such as hackers, viruses, malware, theft, sabotage etc. Data security can be enhanced by various techniques such as encryption, authentication, authorization, auditing, firewalls etc.
Data Integrity
Data integrity is the degree to which the data in the database is consistent and valid according to the rules and constraints of the database system. Data integrity is important because it affects the correctness and reliability of the database system. Data integrity can be violated by various causes such as human errors, system failures, malicious attacks etc. Data integrity can be maintained by various techniques such as integrity constraints, triggers, stored procedures etc.
Data Concurrency
Data concurrency is the degree to which multiple users or applications can access and modify the same data in the database at the same time without interfering with each other. Data concurrency is important because it affects the availability and efficiency of the database system. Data concurrency can cause various problems such as lost updates, uncommitted dependencies, inconsistent retrievals etc. Data concurrency can be controlled by various techniques such as locking, timestamping, serialization etc.
Data Recovery
Data recovery is the degree to which the data in the database can be restored to a consistent state after a failure or disaster. Data recovery is important because it affects the durability and reliability of the database system. Data recovery can be challenged by various types of failures such as hardware failures, software failures, power failures, natural disasters etc. Data recovery can be achieved by various techniques such as backup, restore, checkpointing, logging etc.
Data Performance
Data performance is the degree to which the data in the database can be accessed and manipulated efficiently and effectively. Data performance is important because it affects the usability and satisfaction of the database system. Data performance can be influenced by various factors such as data size, data complexity, data distribution, data access patterns etc. Data performance can be improved by various techniques such as indexing, partitioning, compression, caching etc.
Web Databases and Data Warehousing
The book also covers some of the emerging topics in database systems such as web databases and data warehousing. Web databases are databases that are accessed from or integrated with web applications or services. Data warehousing is a process of collecting, integrating, and analyzing large amounts of data from various sources for business intelligence purposes.
Web Databases
Web databases are databases that are designed for web-based applications or services. Web databases have some unique characteristics and challenges such as:
They are distributed across different locations and platforms.
They are accessed by multiple users with different needs and preferences.
They are dynamic and constantly changing.
They are heterogeneous and diverse in structure and content.
They are subject to various security and privacy risks.
The book covers various technologies and techniques for creating and Web Databases
Web databases are databases that are designed for web-based applications or services. Web databases have some unique characteristics and challenges such as:
They are distributed across different locations and platforms.
They are accessed by multiple users with different needs and preferences.
They are dynamic and constantly changing.
They are heterogeneous and diverse in structure and content.
They are subject to various security and privacy risks.
The book covers various technologies and techniques for creating and accessing web databases, such as:
JDBC (Java Database Connectivity) is a Java API that allows Java applications to connect to and interact with various types of databases using SQL.
SQLJ (SQL for Java) is a Java extension that allows embedded SQL statements in Java code.
ASP (Active Server Pages) is a Microsoft technology that allows dynamic web pages to be generated using server-side scripts that can access databases using ADO (ActiveX Data Objects).
ISP (Internet Server API) is a Microsoft technology that allows low-level access to web servers and databases using C/C++ code.
PSP (PL/SQL Server Pages) is an Oracle technology that allows dynamic web pages to be generated using PL/SQL code that can access Oracle databases.
Data Warehousing
Data warehousing is a process of collecting, integrating, and analyzing large amounts of data from various sources for business intelligence purposes. Data warehousing has some benefits and challenges such as:
It provides a centralized and consistent view of the data across the organization.
It supports decision making and strategic planning by providing historical, current, and predictive insights.
It requires a complex and costly infrastructure and maintenance.
It involves various technical and organizational issues such as data quality, data integration, data modeling, data security, data governance etc.
The book covers various concepts and techniques for designing and implementing data warehouses, such as:
Data warehouse architecture: The logical and physical structure of the data warehouse, such as the data sources, the data staging area, the data warehouse database, the data marts, the metadata repository etc.
Data warehouse design: The process of defining the schema, the granularity, the dimensionality, the hierarchy, the aggregation etc. of the data warehouse database using techniques such as star schema, snowflake schema etc.
Data warehouse implementation: The process of extracting, transforming, loading (ETL), refreshing, and querying the data warehouse database using tools such as Informatica PowerCenter , Oracle Warehouse Builder , Microsoft SQL Server Integration Services etc.
Data warehouse management: The process of ensuring the quality, security, integrity, performance etc. of the data warehouse database using techniques such as data cleansing , data auditing , data backup , data partitioning etc.
Object-Oriented Databases and XML
The book also covers some of the alternative topics in database systems such as object-oriented databases and XML. Object-oriented databases are databases that store d