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C H A P T E R

5. C H A P T E R. Organized Data and Information. Data. Data A necessity for almost any enterprise to carry out its business. Consists of raw facts , and when organized may be transformed into information. Database A collection of data organized to meet users’ needs. Data Management.

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C H A P T E R

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  1. 5 C H A P T E R Organized Data and Information

  2. Data • Data • A necessity for almost any enterprise to carry out its business. Consists of raw facts, and when organized may be transformed into information. • Database • A collection of data organized to meet users’ needs

  3. Data Management • In order to manage data it must be organized. • It is organized in a hierarchy.

  4. The Hierarchy of Data Checking Account Files Savings Account Files Loan Account Files Database 27439, Smith, Joe, 453.21, 1-3-98 34278, Watt, Carol, 212.54, 2-6-99 43872, Yos, Tom, 3224.87, 3-8-97 Files (TABLES) Records 27439, Smith, Joe, 453.21, 1-3-98 Fields Smith (Last Name) (S = 01010011 in ASCII) Characters

  5. The Hierarchy of Data Database A collection of integrated and related files. File A collection of related records. Record A collection of related fields. Field A group of characters. Character Basic building block of information, represented by a byte.

  6. How Characters are Stored • Codes for Storing Data • ASCII • American Standard Code for Information Interchange. • 8 bit code. (256 characters can be represented). • In the early years of computers, it was the most popular code but it was limited to how many characters it could represent. ASCII is still very much used today but it has be extended from 8 bits to 16 bits. With 16 bits, over 65,536characters can be represented.

  7. How Characters are Stored Codes for Storing Data CharacterASCII A 01000001 B 01000010 ... Z 01011010 0 00110000 1 00110001 ... 9 00111001

  8. How Characters are Stored • Codes for Storing Data • UNICODE • UNICODE: Universal Code. • Today, it is the most popular code. • Used by most computer manufactures. • 16 bit code. (65,536 characters can be represented) • A 16 bit code will allow for other languages to • be represented in the code, not just English.

  9. How Characters are Stored Codes for Storing Data Character UNICODE A 0000000001000001 B 0000000001000010 ... Z 0000000001011010 0 0000000000110000 1 0000000000110001 ... 9 0000000000111001 Note that the right-most bits are ASCII within UNICODE. Note the red bits.

  10. Data Files Reports Application Program The Traditional Approach to Data Management • The Traditional Approach • Separate files are created and stored for each application program. • Very common from the 50’s through the 80’s.

  11. The Traditional (File Oriented) ApproachBanking Example Smalltown National Bank 1965

  12. Checking Files Checking Programs Checking Reports Savings Files Savings Programs Savings Reports Loan Files Loan Programs Loan Reports The Traditional (File Oriented) ApproachBanking Example

  13. Checking Files Checking Programs Checking Reports Savings Files Savings Programs Savings Reports Loan Files Loan Programs Loan Reports The Traditional (File Oriented) Approach • PROBLEMS • (1) DATA REDUNDANCY • Same data stored on different files. • Name is on checking, savings, and loan files. • Address is on checking, savings, and loan files. • Telephone number is on checking, savings, and loan files.

  14. Checking Files Checking Programs Checking Reports Savings Files Savings Programs Savings Reports Loan Files Loan Programs Loan Reports The Traditional (File Oriented) Approach • PROBLEMS • DATA REDUNDANCY CAUSES: • Unnecessary data entry. • Duplicated data on one file may not get changed on another file • during an update or deletion. • Leads to a lack in DATA INTEGRITY.

  15. Checking Files Checking Programs Checking Reports Savings Files Savings Programs Savings Reports Loan Files Loan Programs Loan Reports The Traditional (File Oriented) Approach • PROBLEMS • (2) DATA INTEGRITY • Data redundancy leads to a lack of data integrity. • Lack of data integrity = errors in database

  16. Checking Files Checking Programs Checking Reports Savings Files Savings Programs Savings Reports Loan Files Loan Programs Loan Reports The Traditional (File Oriented) Approach • PROBLEMS • (3) LACK OF DATA INTEGRATION • With separate file systems, it is difficult to produce reports which require data from separate file systems. • EXAMPLE: The bank manager might want a report showing the names of customers who use all the bank's services: checking, savings and loans. • In order to collect this information for a report, a separate computer • program would need to be written and this take time.

  17. Checking Files Checking Programs Checking Reports Savings Files Savings Programs Savings Reports Loan Files Loan Programs Loan Reports The Traditional (File Oriented) Approach • PROBLEMS • (4) PROGRAM-DATA DEPENDENCE • If the size of a field in a record changes, all the programs which access that record must be modified. • EXAMPLE: When ZIP codes changed from 5 digits to 9 digits, all programs which accessed ZIP codes had to be modified. Note: When the ZIP code changed, millions of programs needed to be changed in corporations, governments, etc.

  18. Checking Files Checking Programs Checking Reports Savings Files Savings Programs Savings Reports Loan Files Loan Programs Loan Reports The Traditional (File Oriented) Approach SUMMARY (1) CAUSES DATA REDUNDANCY. (2) LACKS DATA INTEGRITY. (3) LACKS DATA INTEGRATION. (4) CAUSES PROGRAM-DATA DEPENDENCY.

  19. Checking Programs Reports Database Management System DBMS All Data Savings Programs Reports Loan Programs Reports The Database Approach • The Database Management System Approach • A pool of related data is shared by multiple application programs. Rather than having separate data files, each application uses a collection of data that is either joined or related in the database. • A DBMS “knows” everything about the data on the hard storage drive/s, and has complete control over it. Hard drive/s

  20. Advantages to the Database Approach • Improved strategic use of corporate data • Reduced data redundancy • Improved data integrity • Easier modification and updating • Data and program independence • Better access to data and information • Standardization of data access • A framework for program development • Better overall protection of the data • Shared data and information resources

  21. Disadvantages to the Database Approach • Increased vulnerability. Unauthorized people hack into • databases on a regular bases. • Foolishly, employees place databases on their laptops which • are stolen when left in cars or unattended at coffee shops. • LoJack Tracking Software • LoJack Video 2min cc (Good) • LoJack Video 4min cc (Very Good) Kensington port • Kensington Lock • Great for coffee shops • The cable is retractable. Just • wrap the cable around a table • post and into the Kensington port on your • computer; then lock the cable into the port. $39 to $21

  22. Employees Checking Stocks Executives Students Attributes Customer name, Employee name Customers Patients Books Inventory Database Terms TABLES (Also called ENTITIES) • A generalized class of people, places, things, or events (objects) about which data are collected, stored, and maintained.

  23. Checking Table Database Terms • FIELDS (Also called ATTRIBUTES) • An Field is a property of an Table. Fields CHECKING TABLE Acct #LastFirstBalanceStart Date 27439 Smith Joe 453.21 1-3-2000 34278 Watt Carol 212.54 2-6-2001 43872 Yos Tom 224.87 3-8-2011

  24. Checking Table Database Terms RECORDS Consist of one or more related Fields in a Table Three records in a Table CHECKING TABLE Acct #LastFirstBalanceStart Date 27439 Smith Joe 453.21 1-3-2000 34278 Watt Carol 212.54 2-6-2001 43872 Yos Tom 224.87 3-8-2011

  25. Database Terms • PRIMARY KEY • A field or set of fields that UNIQUELY identifies the record. • Account Number is the only UNIQUE field in this record. Primary Key CHECKING TABLE Acct #LastFirstBalanceStart Date 27439 Smith Joe 453.21 1-3-2000 34278 Watt Carol 212.54 2-6-2001 43872 Yos Tom 224.87 3-8-2011 .

  26. Database Terms • SECONDARY KEY • A Key which is NOT a primary key. How much money do I have in my checking account? I can’t remember my checking account number, but my last name is Yos. CHECKING TABLE Acct #LastFirstBalanceStart Date 27439 Smith Joe 453.21 1-3-2000 34278 Watt Carol 212.54 2-6-2001 43872 Yos Tom 224.87 3-8-2011 .

  27. Database Terms • KEY • A field or set of fields that is used to identify a record or records. • It is possible to search for any record using any of these five fields. Keys CHECKING TABLE Acct #LastFirstBalanceStart Date 27439 Smith Joe 453.21 1-3-2000 34278 Watt Carol 212.54 2-6-2001 43872 Yos Tom 224.87 3-8-2011 .

  28. Database Terms • DATA ITEM • A specific value of an Field. Data Item (Examples) CHECKING TABLE Acct #LastFirstBalanceStart Date 27439 Smith Joe 453.21 1-3-2000 34278 Watt Carol 212.54 2-6-2001 43872 Yos Tom 224.87 3-8-2011 .

  29. Database Terms • DATA MODELING • This is map or diagram of entities and their relationships. • These maps or diagrams show the how the database is organized. • A popular diagramming technique is called “entity-relationship diagram.” • A MODEL of the database is constructed before the actual database is designed. One popular modeling method is called • an entity-relationship diagram. Entity-relationship diagram .

  30. Database Terms Entity-relationship diagram Name Dept Student Course Takes Class Major 1 N Name Section ID Relation- ship Entity Attribute

  31. Entity Relationship (ER) Diagram for a Customer Ordering Database Attributes (Properties) (Tables) Entities Relationship: Each Customer may order many of the Product

  32. 313-46-2007 412-48-1778 543-56-8876 A Relational Data Model • Relational Data Model • All data elements are placed in two-dimensional tables, called relations, that are the logical equivalent of files.

  33. 313-46-2007 412-48-1778 543-56-8876 Relational Database Terms • Joining • Data manipulation that combines two or more tables. • These three tables can be joined using a common field such as Dept. number. • Example: Using Project number (155) we can find out the description of the project and for what department the project was conducted. This can be done easily even though the data is within two separate files. • See the next slide to see how easy joining can be done using a query language called SQL. (Pronounce S-Q-L or “sequel”) SQL is in all database management systems, including Access.

  34. SELECT DESCRIPTION, DEPT NAME FROM PROJECT, DEPARTMENT WHERE PROJECT NUMBER = 155 AND PROJECT.DEPT NUMBER = DEPARTMENT.DEPT NUMBER PAYROLL ACCOUNTING Dept Number Dept Number 313-46-2007 412-48-1778 543-56-8876 Database Terms • SQL EXAMPLE: • This example shows how to join two • tables using SQL in order to find the Project name and the Department in which the Project was conducted. • Note that the Description of the project (Payroll) was in the Project table and the Dept Name (Accounting) was in the Department table. • The tables were joined using • the Dept Number field. Result .

  35. Database Terms .

  36. Database Terms .

  37. Database Terms .

  38. Database Terms • Distributed Database • A database in which the actual data may be spread across several smaller databases connected via telecommunications devices.

  39. Database Terms • Data Warehouse • A relational database management system. • Designed SPECIFICALLY to support management decision making. • Does NOT meet the needs of a TPS. • Contains massive amounts of current and historical data. Looks as if we should relocate our manufacturing facility to China.

  40. Database Terms • Data Mining • AUTOMATED discovery of patterns and relationships in a data warehouse. • Uses advanced statistical techniques and machine learning. • Used to predict as well as discover. • Data Mining the Internet is now being used by some • companies to predict the future. Look. I think we are experiencing a large increase in credit card fraud.

  41. Data Modeling and Database Models • Data Model • A map or diagram of entities and their relationships. • Enterprise Data Modeling • Data modeling done at the level of the entire organization. • Entity-Relationship (ER) diagrams • A data model that uses basic graphical symbols to show the organization of and relationships between data.

  42. Sample Test Questions DBMS Database 1. In the SQL statement below, which item is an entity? SELECT EMPLOYEE-NUMBER FROM EMPLOYEE WHERE SALARY > 20,000 a. SALARY b. EMPLOYEE c. EMPLOYEE-NUMBER d. a and b e. a, b, and c

  43. Sample Test Questions DBMS • 2. Which item below is most closely associated • with changing the zip code from 5 to 9 digits • in a file-oriented database? • a. Program-data dependence • b. Data integrity • c. Data redundancy • d. Data integration • e. None of the above

  44. Sample Test Questions DBMS 3. When designing a database, which item below would most likely be used to show the logical relationships among data? a. Access 2003 b. Entity-relationship diagrams c. Data Manipulation Language (DML) d. System Flowcharts e. Data Definition Language (DDL)

  45. Sample Test Questions DBMS 4. What is the main use for data warehouses? a. To meet the needs of day-to-day transaction processing. b. To support the needs of management decision making. c. To store all of a company’s transactions. d. None of the above

  46. Sample Test Questions DBMS 5. Which system below would be best for detecting credit card transactions which are likely to be fraudulent? a. Data mining b. Pattern analysis c. Pattern mining d. Data Marting e. Transaction processing system

  47. Sample Test Questions DBMS 6. What database model places data in two-dimensional tables? a. relational b. network c. hierarchical

  48. Sample Test Questions DBMS 7. In order to do a "join" in a relational database, it is necessary to have: a. some data redundancy. b. some program-data dependency. c. some errors in the database d. None of the above

  49. Sample Test Questions DBMS 8. This type of database key must be unique: a. Primary Key b. Secondary Key c. Tertiary Key d. a and c e. a, b, and c

  50. Sample Test Questions DBMS 9. With this database configuration, the files are placed in multiple locations within the organization. a. Centralized configuration b. Distributed configuration c. Hierarchical configuration d. a and c e. b and c

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