【正文】 darshan Database System Concepts Representation of Information ? Data is collections of bits ? physical database ? Information is data with meaning ? logical database ? Representation of metadata ? database system is selfdescribing ? Database Management System (DBMS) ? define information content ? construct database ? manipulate by queries, reports and updates ? data plus software 169。P 500 and Microsoft ? This picture is the stock performance, as shown on the BigCharts Web site from July, 1999 to July, 2020 169。Silberschatz, Korth and Sudarshan Database System Concepts Importance of Databases to Economy ? Expanding use of databases in retail sales ? Walmart, retail sales information tracking ? LL Bean, catalog sales information tracking ? Examples of analyses ? Sales of items ? Comparisons between daily totals of items sold and items in inventory ? Seasonal variations in sales of specific and similar items ? Relative sales of similar items with different features ? Marketbasket collections (all items in a single purchase) ? Average and variation in total purchase amount ? Average and variation in number and price of items ? Correlation between sales of items in a single purchase ? Customer analysis ? Behavior of average customer ? Preferences of individual customers 169。Silberschatz, Korth and Sudarshan Database System Concepts Current Events ? Each lecture will cover current events that affect the database industry ? Please bring info to lectures and recitations 169。Silberschatz, Korth and Sudarshan Database System Concepts Textbook and class meetings ? Main Text:A. Silberschatz, . Korth, S. Sudershan: Database System Concepts, 5th ed., McGrawHill, 2020 ? Reference:1. , Introduction to datamining,Addison Wesley,2020. ? of Database Systems With Inter and Java Applications ? by Greg Riccardi ? 2020, AddisonWesley ? Lectures and recitations 169。Silberschatz, Korth and Sudarshan Database System Concepts 169。Silberschatz, Korth and Sudarshan Database System Concepts 169。Silberschatz, Korth and Sudarshan Database System Concepts 169。Silberschatz, Korth and Sudarshan Database System Concepts ??! Your evaluation in this course is determined by: 30% Class Presentation 10% Presentation report 5% Cover your presentation Thursday 169。CS157B Lecture 1 Prof. SinMin Lee Department of Computer Science San Jose State University 169。Silberschatz, Korth and Sudarshan Database System Concepts Tuesday Thursday 10:15 – 11:30 Also by appointment 169。Silberschatz, Korth and Sudarshan Database System Concepts You are required to write up your report using LaTeX. LaTeX is the standard tool for typesetting scientific articles. Read Inventor of TeX 169。Silberschatz, Korth and Sudarshan Database System Concepts ?? Sometimes 169。Silberschatz, Korth and Sudarshan Database System Concepts 169。Silberschatz, Korth and Sudarshan Database System Concepts Outline of Course ? Study of principals and techniques of databases ? Grades assigned as in information sheet ? Examples of use of databases ? Programming projects in database design and implementation ? Programming in Microsoft Access ? Programming in Java with Oracle ? Development of a web site with database support 169。Silberschatz, Korth and Sudarshan Database System Concepts Students’ Role in Class ? Attend class, please. ? The class notes are available, but they are not the full classroom experience ? Recitation sections are provided to personalize and enhance your learning environment ? You are paying for this, take advantage of it ? Read the book. ? There are many topics covered in the text, but not the lectures ? There are many details and examples in the text ? Seek help during office hours 169。Silberschatz, Korth and Sudarshan Database System Concepts Why Study Files and Databases? ? Next few slides address the following ? Importance of Databases to Economy ? Can you get a job in the database field? ? Representation of Information ? Add meaning to data ? Management of Complexity ? Divide system into layers, focus on data ? Management of Access and Security ? Efficiency of Access and Storage ? Separate data, allow optimizations 169。Silberschatz, Korth and Sudarshan Database System Concepts Importance of Database Companies ? Oracle is the 2nd largest software pany ? It’s stock has outperformed Samp。Silberschatz, Korth and Sudarshan Database System Concepts E merce ? Companies are fighting for the market ? See Oracle Web site ? See IBM Web site ? XML and XSL at Microsoft ? ? ? 169。Silberschatz, Korth and Sudarshan Database System Concepts Management of Complexity ? Insulation between programs and data ? Programdata independence ? Programoperation independence ? Data abstraction ? conceptual model for users ? physical model for administrators ? Sharing data and multiuser transactions ? People ? Database administrators ? Database designers ? Applications programmers ? End users 169。Silberschatz, Korth and Sudarshan Database System Concepts Efficiency of Access and Storage Cost of Access for Seagate Cheetah Disk ? Seek time ? Move access arm to the cylinder ? Avg 6 msec, min msec ? Rotational delay ? 1000 rpm, one revolution per 6 millisecond ? Average 3 msec ? Total latency max 12 msec, avg 9 msec ? Transfer rate ? 24 Mbytes/sec ? Speed of memory access, Athlon 750 mhz ? Latency 100 nanosecond, 10,000 times faster than disk ? Transfer rate GBytes/sec, 7 times faster than disk 169。Silberschatz, Korth and Sudarshan Database System Concepts Vocabulary ? Glossary of terms ? Define the terms as used in this subject ? Database literature is filled with terms ? Example of terms ? Data, bits ? Information, bits with meaning (type