Presentation is loading. Please wait.

Presentation is loading. Please wait.

Management Information Systems, Sixth Edition Chapter 7: Databases and Data Warehouses.

Similar presentations


Presentation on theme: "Management Information Systems, Sixth Edition Chapter 7: Databases and Data Warehouses."— Presentation transcript:

1 Management Information Systems, Sixth Edition Chapter 7: Databases and Data Warehouses

2 Management Information Systems, Sixth Edition2 Objectives Explain the difference between traditional file organization and the database approach to managing digital data Explain how relational and object-oriented database management systems are used to construct databases, populate them with data, and manipulate the data to produce information Enumerate the most important features and operations of a relational database, the most popular database model

3 Management Information Systems, Sixth Edition3 Objectives (continued) Understand how data modeling and design creates a conceptual blueprint of a database Discuss how databases are used on the Web List the operations involved in transferring data from transactional databases to data warehouses

4 Man age ment Infor mati on Syst ems, Sixth Editi on 4 Shine in 10 (Activity 7) Define IYOW any of the following that is assigned to you: 1.Database approach vs Traditional file approach 2.Hierarchy of Data (Show the hierarchy and examples) 3.Primary, Composite and Foreign keys 4.SQL (what it does and how it works) 5.ERD (how it is used – be specific) 6.Data Warehouse This is worth 20pts

5 Management Information Systems, Sixth Edition5 Managing Digital Data Businesses collect and dissect data for many purposes Data can be stored in database format –Easy access and manipulation Databases have had a profound impact on business –An information industry has been created Database technology integrated with the Internet has contributed to commerce significantly

6 Management Information Systems, Sixth Edition6 The Traditional File Approach Traditional file approach: no mechanism for tagging, retrieving, or manipulating data Database approach: provides powerful mechanism for managing and manipulating data Traditional approach is inconvenient: –Program-data dependency –High data redundancy –Low data integrity Data redundancy: duplication of data Data integrity: accuracy of data

7 Management Information Systems, Sixth Edition7 The Traditional File Approach (continued)

8 Management Information Systems, Sixth Edition8 The Database Approach Database approach: data organized as entities Entity: an object about which an organization chooses to collect data, such as: –People –Events –Products Character: smallest piece of data –A single letter or a digit Field: single piece of information about entity

9 Management Information Systems, Sixth Edition9 The Database Approach (continued) Record: collection of related fields File: collection of related records Database fields can hold images, sounds, video clips, etc. Field name allows easy access to the data Database management system (DBMS): program used to: –Build databases –Populate a database with data –Manipulate data in a database

10 Management Information Systems, Sixth Edition10

11 Management Information Systems, Sixth Edition11

12 Management Information Systems, Sixth Edition12 The Database Approach (continued) Query: a message to the database requesting data from specific records and/or fields Database must be properly secured –Not everyone should have access to all data –Users will have different views of the database, based on the data they are allowed to see

13 Management Information Systems, Sixth Edition13 The Database Approach (continued) Visual Query from MS Access

14 Management Information Systems, Sixth Edition14 The Database Approach (continued) Database administrator (DBA): the person responsible for managing the database –Sets user limits for access to data in the database DBMS is usually bundled with a programming language

15 Management Information Systems, Sixth Edition15

16 Management Information Systems, Sixth Edition16

17 Management Information Systems, Sixth Edition17 Database Models Database model: general logical structure –How records stored in the database –How relationships between records are established Database models differ in: –How records are linked to each other –How users can navigate the database, retrieve records, and create records

18 Management Information Systems, Sixth Edition18 The Relational Model Relational Model: consists of tables Based on relational algebra –Tuple: record (or row) –Attribute: field (or column) –Relation: table of records To design a relational database, you must understand the entities to be stored in the database and how they relate Tables are independent of each other, but can be related to each other

19 Management Information Systems, Sixth Edition19 The Relational Model (continued) Key: a field whose values identify records –Used to retrieve records Primary key: a field by which records are uniquely identified –Each record in the table must have a unique key value Composite key: combination of fields that serve as a primary key

20 Management Information Systems, Sixth Edition20

21 Management Information Systems, Sixth Edition21 The Relational Model (continued)

22 Management Information Systems, Sixth Edition22 The Relational Model (continued) Foreign key: a field that is common to two tables –Used to link the tables –This field is a primary key in one table and a foreign key in the other Join table: composite of tables Two types of table relationships: –One-to-many relationship: one item in a table is linked to many items in the other table –Many-to-many relationship: many items in a table are linked to many items of the other table

23 Management Information Systems, Sixth Edition23 The Relational Model (continued) Related One-to-Many Table in MS Access Primary Key Foreign Key

24 Management Information Systems, Sixth Edition24 The Relational Model (continued)

25 Management Information Systems, Sixth Edition25 The Object-Oriented Model Object-oriented database model: uses object- oriented approach for the database structure Encapsulation: combined storage of data and relevant procedures to process it –Allows object to be “planted” in different data sets Inheritance: the ability to create a new object by replicating the characteristics of an existing (parent) object Object-oriented databases (ODBs) store data objects, not records

26 Management Information Systems, Sixth Edition26

27 Management Information Systems, Sixth Edition27 Relational Operations Relational operation: creates a temporary subset of a table or tables Used to create a limited list or a joined table list Three important relational operations: –Select: a selection of records based on conditions –Project: a selection of certain columns from a table –Join: join data from multiple tables to create a temporary table

28 Management Information Systems, Sixth Edition28 Structured Query Language Structured Query Language (SQL): query language of choice for DBMSs Advantages of SQL: –It is an international standard –It is provided with most relational DBMSs –It has easy-to-remember, intuitive commands

29 Management Information Systems, Sixth Edition29 Structured Query Language SQL in MS Access

30 Management Information Systems, Sixth Edition30 Structured Query Language

31 Management Information Systems, Sixth Edition31 The Schema and Metadata Schema: a plan that describes the structure of the database, including: –Names and sizes of fields –Identification of primary keys –Relationships Data dictionary: a repository of information about the data and its organization –Also called metadata: the data about the data

32 Management Information Systems, Sixth Edition32 The Schema and Metadata (continued) Metadata includes: –Source of the data –Tables related to the data –Field and index information –Programs and processes that use the data –Population rules: what is inserted, or updated, and how often

33 Management Information Systems, Sixth Edition33

34 Management Information Systems, Sixth Edition34 Data Modeling Databases must be carefully planned and designed to meet business goals Data modeling: analysis of an organization’s data and identification of the data relationships –A proactive process –Develops a conceptual blueprint of the database Entity relationship diagram: a graphical representation of all entity relationships

35 Building Blocks of ERD 35 TypeEnglish Grammar EquivalentExample EntityProper NounStudent, Employee, Instructor, Courses, Room RelationshipVerbhas, teaches, belongs, handles AttributeAdjectiveHeight, Age, Gender, Nationality, First name

36 ERD Popular Notation Chen Notation Crow’s Foot Notation 36

37 Chen Notation - Symbol 37 1M Rectangle represents an Entity Diamond represents a Relationship Lines with labels represents Cardinality

38 Entity (Chen Notation) is a real-world object distinguishable or unique from other objects. An entity can be a concrete or physical object like employee, student, faculty, customer etc. Or it could also be conceptual or abstract like transaction, order, course, subjects etc. It can be thought of as a noun like student, employee etc. It is normally represented by a rectangle shape. 38

39 Database Background –Entity could be a : 39 Person Place (ex. Teacher, Student, Physician) (ex. School, Hotel, Store ) Object (ex. Mouse, Books, Bulding ) Event (ex. Enroll, Withdraw, Order ) Idea or Concept (ex. Courses, Account, Delivery )

40 Entity - Example 40 CustomerSales Rep Order Parts

41 Relationship is a way of relating one entity to another. Entities can therefore participate in a relationship. it is commonly thought as a verb connecting the entities or nouns. It is normally represented by a diamond shape. 41

42 Relationship - Example 42 represents Customer Sales Rep Order has Could be read as : A Sales Rep Represents a Customer. And a Customer has an Order.

43 Cardinality Cardinality: number of items that must be included in a relationship –An entity in a relationship with minimum cardinality of zero plays an optional role in the relationship –An entity with a minimum cardinality of one plays a mandatory role in the relationship 43

44 Cardinality - Symbols 44 One-is-to-many Relationship 1M MN Many-to-many Relationship

45 Cardinality Symbols - Example 45 represents Customer Sales Rep Could be read as : A Sales Rep could represent 1 or Many Customers. 1M

46 Cardinality Symbols – Example (Cont’d) 46 has Parts Order Could be read as : An Order could have many Parts (e.g. Products Ordered) and a Part could have many Orders. MN

47 Degree of Relationship There are three Degree of Relationships in ERD notation, namely: –Unary –Binary –Ternary 47

48 Degree of Relationship (Cont’d) 48 Unary Binary Ternary

49 Degree of Relationship (Cont’d) 49 Employee Unary CustomerOrders Binary Vendor Warehouse Part Ternary Manages makes supplies

50 Attribute Refers to the characteristic or basic fact or field of an Entity or Relationship. For example a Student entity could have the following attributes ID Number, Last Name, First Name, Address, Birth Date etc. A relationship could also have an attribute for example an Entity name Student enrolls (relationship) to a Course/Program. Now, when you enroll you enroll on a certain date so you will have an attribute of Enrollment Date under Enroll relationship. It is normally represented by an oval. 50

51 Attribute - Example 51 RepNum Sales Rep Lastname Firstname Street City State Zip Commission Rate Take note that a Primary Key is underlined.

52 Attribute – More Example 52 RepNum Sales Rep Lastname Firstname Street City State Zip Commission Rate Customer represents CustomerNum CustomerName CreditLimit Balance Street City State Zip 1M

53 Crow’s Foot notation - Symbol 53 Entity name Attribute 1 Attribute 2 Attribute 3 Attribute 4

54 Crow’s Foot notation - Example 54 Student StudentID Firstname Lastname Gender Program Entity Attributes

55 Crow’s Foot notation - Keys 55 Student StudentID (PK) Firstname Lastname Gender ProgramID (FK) PK – Primary Key FK – Foreign Key

56 Crow’s Foot Cardinality - Symbols 56 One and only one included in the relationship Zero or many could be included in the relationship. This is optional mode. One or many could be included in the relationship. This is mandatory mode.

57 Crow’s Foot notation – with Cardinality 57 Rep Repnum (PK) Firstname Lastname Commission Rate Customer Customernum(PK) Customername Street City State Zip Balance CreditLimit Repnum (FK)

58 Management Information Systems, Sixth Edition58 Mini-Project 2 – ERD Create an ERD for your Case Study in Gardeners+ that you started on chapter 1. Identity the different entities and the relationship among these entities. This is worth 50 points and below is the criteria on how are you going to be graded Criteria : ERD reflects real world entities or all entities are properly identified- 40% Relationships are well defined- 30% Attributes are complete and well defined- 30% TOTAL100% Note : Make sure that standard of integrity is followed in your project as mentioned in our syllabus. Which means I expect that your work should be your work and not of the others. However, it does not mean you could not consult your classmates. You could consult one or two of your classmates but make sure that it is a matter of clarification or technicality. A high degree of similarity with at least one of your Classmates, I would consider as copying or plagiarism and therefore will be dealt with accordingly, that is, it would merit a deductions both on you and your classmate where you copied your work.

59 Management Information Systems, Sixth Edition59 Mini-Project No. 3 - Database Creating the Gardeners+ Database Create a Database for your case study based on your ERD that you have just created Create tables that reflects an entity, namely, People, Event or Products Create a relationship among tables You could use MS Access or MySQL Database Management Systems on this one. This is worth 50 points and the criteria for your grading is shown below: Criteria : Tables reflects real world entities- 40% Table Relationships are rightly defined- 40% Complete sets of tables are defined - 20% TOTAL100% Note : Make sure that standard of integrity is followed in your project as mentioned in our syllabus. Which means I expect that your work should be your work and not of the others. However, it does not mean you could not consult your classmates. You could consult one or two of your classmates but make sure that it is a matter of clarification or technicality. A high degree of similarity with at least one of your Classmates, I would consider as copying or plagiarism and therefore will be dealt with accordingly, that is, it would merit a deductions both on you and your classmate where you copied your work.

60 Management Information Systems, Sixth Edition60 Databases on the Web Web is dependent on databases –Organizations must link their databases to the Web Interface between Web and database required Interface may be programmed in one of several Web programming languages, including: –Java servlets –Active server pages (ASP) –PHP (Hypertext Preprocessor) –Web application program interfaces (APIs)

61 Management Information Systems, Sixth Edition61 Databases on the Web (continued)

62 Management Information Systems, Sixth Edition62 Data Warehousing Most data collections are used for transactions Accumulation of transaction data is useful Data warehouse: a large repository database that supports management decision making –Typically relational –Data is collected from transactional databases Data mart: a smaller collection of data focusing on a particular subject or department

63 Management Information Systems, Sixth Edition63 From Database to Data Warehouse Transactional databases are not suitable for business analysis –Contain only current, not historical data Data warehouse requires large storage capacity: –Mainframe computers are often used –Scalability is an issue –Data warehouses grow continually

64 Management Information Systems, Sixth Edition64 Phases in Data Warehousing Three phases in transferring data from a transactional database to a data warehouse: –Extraction phase: create files from transactional database –Transformation phase: cleanse and modify the data format –Loading phase: transfer files to data warehouse A properly built data warehouse becomes a single source for all data required for analysis Data mining and online analytical processing (OLAP) use data in data warehouses

65 Management Information Systems, Sixth Edition65

66 Management Information Systems, Sixth Edition66 VB.net Database Demo

67 Management Information Systems, Sixth Edition67 MS Access Demo

68 Management Information Systems, Sixth Edition68 Summary Organizations collect vast amounts of data Database approach has several advantages over traditional file approach Character: smallest piece of data Field: made up of multiple characters Record: collection of related fields File: collection of related records Database management system (DBMS): tool to construct databases

69 Management Information Systems, Sixth Edition69 Summary (continued) Relational and object-oriented database models have different advantages Keys are used to form links among entities Primary keys are unique identifiers Object-oriented database maintains objects that contain data and procedures that process it Structured Query Language (SQL) is an international standard for querying databases Database designer must construct a schema to construct a database

70 Management Information Systems, Sixth Edition70 Summary (continued) Database designers conduct data modeling and create entity relationship diagrams to plan databases Many databases are linked to Web Data warehouses contain huge collections of historical transaction data Data warehouse requires data extraction, transformation, and loading of transactional data Invasion of privacy is exacerbated by database technology


Download ppt "Management Information Systems, Sixth Edition Chapter 7: Databases and Data Warehouses."

Similar presentations


Ads by Google