Tài liệu Module 4: Building Dimensions Using the Dimension Editor ppt

Contents Overview 1 Understanding Dimension Basics 2 Shared vs. Private Dimensions 8 Working with Standard Dimensions 11 Basic Level Properties 13 Lab A: Creating a Standard Dimension 24 Lab B: Creating a Snowflake Dimension 28 Working with Parent-Child Dimensions 32 Lab C: Creating a Parent-Child Dimension 38 Review 45 Module 4: Building Dimensions Using the Dimension Editor BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY Information in this document is subject to change -without notice. The names of companies, products, people, characters, and/or data mentioned herein are fictitious and are in no way intended to represent any real individual, company, product, or event, unless otherwise noted. Complying with all applicable copyright laws is the responsibility of the user. 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Microsoft is listed first, followed by all other Microsoft trademarks in alphabetical order. > are either registered trademarks or trademarks of Microsoft Corporation in the U.S.A. and/or other countries. <This is where mention of specific, contractually obligated to, third party trademarks, which are added by the Copy Editor> The names of companies, products, people, characters, and/or data mentioned herein are fictitious and are in no way intended to represent any real individual, company, product, or event, unless otherwise noted. Other product and company names mentioned herein may be the trademarks of their respective owners. Module 4: Building Dimensions Using the Dimension Editor iii BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY Instructor Notes Dimensions are the fundamental beginning point for building an online analytical processing (OLAP) cube in Microsoft ® SQL Server ™ 2000 Analysis Services. Cubes contain multiple dimensions, which may be either shared or private, star or snowflake, regular or parent-child. In this module, students learn how to build dimensions by using the Dimension Editor. You dissect the building blocks of dimensions for students in detail. When they have completed this module, students will feel comfortable with all aspects of dimension interfaces. In the labs, students create two dimensions by using the Dimension Editor and two dimensions by using the Dimension Wizard. Students perform various dimension enhancements, such as updating the Member Key Column property, defining sort order, adding levels, and creating member properties. After completing this module, students will be able to: ! Understand dimension fundamentals. ! Know when to use shared and private dimensions. ! Describe the characteristics of standard dimensions. ! Add level properties to dimensions. ! Develop parent-child dimensions. Materials and Preparation This section lists the required materials and preparation tasks that you need to teach this module. Required Materials To teach this module, you need the following materials: ! Microsoft PowerPoint ® file 2074A_04.ppt Preparation Tasks To prepare for this module, you should: ! Read all the student materials. ! Read the instructor notes and margin notes. ! Complete the demonstration. ! Practice the lecture presentation and demonstration. ! Complete the labs. ! Review the Trainer Preparation presentation for this module on the Trainer Materials compact disc. ! Review any relevant white papers that are located on the Trainer Materials compact disc. Presentation: 60 Minutes Labs: 60 Minutes iv Module 4: Building Dimensions Using the Dimension Editor BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY Demonstration: Creating a Star Schema Dimension You can create dimensions quickly and easily by using the Dimension Wizard. While the Dimension Wizard is a useful tool for many situations, the Dimension Editor and the Cube Editor are the primary tools for defining and modifying dimensions. The following demonstration procedures provide information that will not fit in the margin notes or are not appropriate for student notes. ! To create a new database and define a data source 1. Open Analysis Manager and double-click the local server. 2. In Analysis Manager, right-click the local server, click New Database, type Module 04 in the Database name box, and then click OK. 3. Double-click Module 04 to expand the database. 4. Right-click the Data Sources folder, and then click New Data Source. 5. On the Provider tab of the Data Link Properties dialog box, click Microsoft OLE DB Provider for SQL Server, and then click Next. 6. Type localhost in the server name box, click Use Windows NT Integrated security, click Module 04 in the Select the database on the server list, and then click OK. ! To create a new dimension 1. In the Module 04 database, right-click the Shared Dimensions folder, point to New Dimension, and then click Editor. 2. Click State as the dimension table in the Choose a Dimension Table dialog box, and then click OK. The left side of the Dimension Editor is divided into two panes. The upper left pane contains the dimension tree that displays levels as you design the dimension. The lower left pane contains dimension properties. If you click the Properties button, the Properties pane disappears or reappears, depending on whether the pane is showing after you open the Dimension Editor. 3. In the Properties pane, the current name of the dimension is <New>. Type State as the name, and then press ENTER. The name of the dimension appears in the dimension tree. 4. Drag State_Name from the State table in the Schema pane onto the name of the State dimension in the dimension tree. This creates a new level in the dimension. 5. Click the State Name level in the dimension tree, type State in the Name box on the Properties pane, and then press ENTER. 6. Click the Data tab at the bottom of the Schema pane. Double-click All State and view the members in the State dimension. 7. On the toolbar, click Save, and then close the Dimension Editor. Demonstration: 5 Minutes Module 4: Building Dimensions Using the Dimension Editor v BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY Other Activities Difficult Questions Below are difficult questions that students may ask you during the delivery of this module and answers to the questions. These materials delve into subjects that are within the scope of the module but are not specifically addressed in the content of the student notes. 1. How many dimensions are typically included in cubes? Normal users cannot digest more than six or seven dimensions in an OLAP report. For this reason, cube designers restrict the number of dimensions in cubes based on user comprehension more often than system limitations. Cubes typically contain four to ten dimensions in production systems. 2. How does Analysis Services handle data sources for cubes that do not contain a dimension, because the dimension information is stored in another system? You must have all dimension tables and fact tables existing in a single relational data source before creating dimensions and cubes. If the dimension exists in a separate system, you can use Data Transformation Services (DTS) to move the dimension from the other system to the source database. You must also be sure that the cube fact table contains keys that map to the dimension table. 3. What options are available for sorting members, other than sorting by the Member Key Column or the Member Name Column properties? If neither the Member Key Column nor the Member Name Column of a dimension provides the correct sort order, you can use a third column to control the sort order. Simply add that column as a member property to the level you want to sort. Member properties for a level automatically appear in the Order by property list. If you build the dimension by using the Dimension Wizard, it gives you the option to select any column from the dimension table to define the sort order, and then the wizard automatically creates the member property for you. 4. What is the best practice for defining members based on expressions? Use expressions as a last resort for defining members. The best practice for updating members is to update the data source so that all systems describe members in the same manner. However, you may have difficulties updating the source database due to administrative policies against such a practice or other external issues. Defining expressions in the Dimension Editor allows you to update members without updating the source database. 5. How can users view the default member of a dimension? When you browse the cube in the Cube Browser, the dimensions in the filter area default to a single member. This member is known as the default member. vi Module 4: Building Dimensions Using the Dimension Editor BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY Module Strategy Use the following strategy to present this module: ! Understanding Dimension Basics Introduce dimensions and the role they play in cube design. Describe how various user communities define and use dimensions. Define levels and members and how they relate to each other. Review dimension and level system limitations. ! Shared vs. Private Dimensions Describe shared dimensions, focusing on their characteristics and when to incorporate them into cubes. Define private dimensions, comparing them to shared dimensions throughout the discussion. Finish the shared dimension and private dimension discussion with a summary statement of when to use each type. ! Working with Standard Dimensions Define standard dimensions, focusing on the use of columns to determine dimension levels. Demonstrate the creation of dimensions by using the Dimension Editor. ! Basic Level Properties Describe the use of Member Key Columns and Member Name Columns when creating dimensions. Discuss how you sort members in levels based upon the key or the name. Introduce creating expressions in Member Key Columns and Member Name Columns to change members. Focus on the rules for creating valid expressions. Define ragged dimensions and how to implement them in standard, balanced dimensions. Define snowflake dimensions and compare them to star schema dimensions. Explain the importance of the All level and discuss situations when not to use it in a dimension. Define the default member and describe situations in which to change it from its original setting. ! Working with Parent-Child Dimensions Introduce parent-child dimensions by giving an example of a situation in which a parent-child dimension is used. Describe the structure of a parent- child dimension. Explain that parent-child dimensions can have values in the fact table at both the leaf level and at a parent level. Introduce the Members with Data property and describe the three values it can have. Explain that there are different options for displaying the levels in a parent- child dimension, and finish up with a description of how the Skipped Levels Column property allows you to create ragged hierarchies in parent- child dimensions. Module 4: Building Dimensions Using the Dimension Editor 1 BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY Overview ! Understanding Dimension Basics ! Shared vs. Private Dimensions ! Working with Standard Dimensions ! Basic Level Properties ! Working with Parent-Child Dimensions Dimensions are the fundamental beginning point for building an online analytical processing (OLAP) cube in Microsoft ® SQL Server ™ 2000 Analysis Services. Cubes contain multiple dimensions, which may be either shared or private, star or snowflake, regular or parent-child. After completing this module, you will be able to: ! Understand dimension fundamentals. ! Know when to use shared and private dimensions. ! Describe the characteristics of standard dimensions. ! Add level properties to dimensions. ! Develop parent-child dimensions. Topic Objective To provide an overview of the module topics and objectives. Lead-in In this module, you will learn about the Dimension Editor and how to use it to create and manage dimensions. 2 Module 4: Building Dimensions Using the Dimension Editor BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY # ## # Understanding Dimension Basics ! Enabling Various Views ! Understanding Levels and Members ! Describing Familial Relationships ! Reviewing Analysis Services Limits A dimension contains levels and members organized into hierarchies. It categorizes the numeric measures stored in a cube. A dimension provides users with a great number of combinations and intersections with which to analyze data. Each dimension describes an aspect of the users’ business and provides intuitive and simple access to data. You design and build each dimension based upon the business processes required by users. A cube requires that you define at least one dimension in its schema. Each cube can have up to 128 dimensions, depending on the business needs of the user community. In OLAP cubes, dimensions: ! Provide a descriptive or analytical view of the key measures in the cube, typically organized around one or more categories relevant to the business. ! Are shared across multiple cubes that may differ across user communities. Examples of commonly shared dimensions are geography, product, time, customer, and scenario. ! Contain varying degrees of summarization, called levels, by which data is viewed. The levels, organized into hierarchies, are frequently described as drill-down paths for the user in search of more specific answers. Topic Objective To introduce the concepts of dimensions, levels, and members. Lead-in A dimension contains levels and members organized into hierarchies. It categorizes the numeric measures stored in a cube. Module 4: Building Dimensions Using the Dimension Editor 3 BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY Enabling Various Views Finance Operations Profit by Division by Country by Month by Actual/Budget Revenue by Product by Region by Sales Rep by Quarter Revenue by Customer by Industry by Channel by Week Sales Marketing Volume by Plant by Shift by Product by Day Analysis Server OLAP cubes answer business questions for summarized data—for example, what were revenues for all drink products in the northeast region in the second quarter? The above illustration shows an Analysis Server and four cubes accessed by four separate user communities—Finance, Sales, Marketing, and Operations. Each of the four groups views a different set of cube data because each group has different business needs. The dimensions defined for each user community categorize the measures of the cube. Every measure is analyzed in terms of every dimension in the cube. An important word used to introduce each dimension is the word by. For example, the Marketing users need to see Revenue: ! By Customer ! By Industry ! By Channel ! By Week Marketing users can report on Revenue as it applies to any of the above dimensions. Topic Objective To illustrate how different groups of users use dimensions. Lead-in Each of the four groups contains a different view of cube data defined by a user community. Delivery Tips Describe each user community as the slide builds the groups one by one. Ask students to describe the important business processes and underlying databases that they work with. Then ask the students to describe the dimensions that would apply to the processes or databases. 4 Module 4: Building Dimensions Using the Dimension Editor BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY Understanding Levels and Members ! Product Dimension ! Four Levels: All, Category, Sub-Category, Product ! Category Members: Bread, Dairy, Meat Dimensions consist of members organized into levels. This organization gives users access to data at different levels of detail. The above illustration shows a dimension, Product that contains the levels All, Category, Sub-Category, and Product. Each level consists of members—for example, the Category level consists of the members Bread, Dairy, and Meat. When defining dimensions, you must understand which levels the users require. In addition, you must determine the tables containing levels and members in the relational data source. In most cases, dimensions have different degrees of summarization or levels, enabling drilling down and drilling up. In a multidimensional database, levels: ! Define the hierarchy of a dimension. ! Are organized by degrees of summarization. For example, Country, State, City, and Zip Code might each be levels in a Region dimension. Users and their required business questions determine the number of dimensions and the number of levels in a dimension. Topic Objective To review the terms level and member and to explain the importance of levels and members in dimension design. Lead-in Dimensions consist of members, organized into levels, and give users access to data at different levels of detail. Review dimension level and members. Quiz students on the levels and members. [...]... and then close the Dimension Editor ! To open the State dimension • In the Module 04 database, double-click the Shared Dimensions folder, right-click State, and then click Edit BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY 26 Module 4: Building Dimensions Using the Dimension Editor ! To update the Member Key Column 1 In the Dimension Editor, click the State level in the dimension. .. Module 4: Building Dimensions Using the Dimension Editor # Shared vs Private Dimensions Topic Objective To introduce the concepts of shared and private dimensions ! Working with Shared Dimensions Lead-in ! Working with Private Dimensions Dimensions are defined as either shared or private at the time they are created The goal of this section is to explain the differences between shared and private dimensions, ... ONLY Module 4: Building Dimensions Using the Dimension Editor 27 ! To update the All level 1 In the dimension tree, click the State dimension 2 On the Advanced tab of the Properties pane, change the All Caption property setting from All State to North America, and then press ENTER 3 On the Dimension Members pane, notice the North America member at the top of the dimension hierarchy ! To make the dimension. .. many situations, the Dimension Editor and the Cube Editor are the primary tools for defining and modifying dimensions In this demonstration, you will learn how to create a standard star schema dimension by using the Dimension Editor instead of the Dimension Wizard BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY Module 4: Building Dimensions Using the Dimension Editor 13 # Basic... Select the database on the server list, and then click OK ! To create a new dimension 1 In the Module 04 database, right-click the Shared Dimensions folder, point to New Dimension, and then click Editor 2 Click State as the dimension table in the Choose a Dimension Table dialog box, and then click OK The left side of the Dimension Editor is divided into two panes The upper left pane contains the dimension. .. Click the Order By box, and then click Key Tip If you build the dimension by using the Dimension Wizard, it gives you the option to select any column from the dimension table to define the sort order, and then the wizard automatically creates the member property for you BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY Module 4: Building Dimensions Using the Dimension Editor. .. shared dimensions in the Analysis Manager interface by the sharing hand icon BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY 10 Module 4: Building Dimensions Using the Dimension Editor Working with Private Dimensions Topic Objective To examine the characteristics of private dimensions ! ! Define the dimensions as private if it is unacceptable for the cube to be unavailable to the. .. as you design the dimension The lower left pane contains dimension properties If you click the Properties button, the Properties pane disappears or reappears, depending on whether the pane is showing after opening the Dimension Editor 3 In the Properties pane, the current name of the dimension is Type State as the name and then press ENTER The name of the dimension appears in the dimension tree... State_Name from the State table in the Schema pane onto the name of the State dimension in the dimension tree This creates a new level in the dimension 5 Select the State Name level in the dimension tree, type State in the Name box on the Properties pane, and then press ENTER 6 Click the Data tab at the bottom of the Schema pane Double-click All State and view the members in the State dimension 7 On the toolbar,... ONLY Module 4: Building Dimensions Using the Dimension Editor 21 Understanding Snowflake Dimensions Topic Objective To describe and illustrate snowflake dimensions Dimension Tables Lead-in When a dimension in a database originates from more than one dimension table, the dimension is called a snowflake dimension Fact Table When a dimension in a database originates from more than one dimension table, the . with. Then ask the students to describe the dimensions that would apply to the processes or databases. 4 Module 4: Building Dimensions Using the Dimension. toolbar, click Save, and then close the Dimension Editor. Demonstration: 5 Minutes Module 4: Building Dimensions Using the Dimension Editor v BETA MATERIALS