tailieunhanh - Microsoft SQL Server 2000 Data Transformation Services- P3

Microsoft SQL Server 2000 Data Transformation Services- P3: Data Transformation Services in Microsoft SQL Server 2000 is a powerful tool for moving data. It’s easy to use, especially when you’re creating transformation packages with the DTS Wizard. But it’s also a flexible tool that you can customize to gain a high degree of control over the transformation of your data. | Getting Started with DTS 76 Part I Multidimensional Database Management Systems OLAP You can create a multidimensional database schema in a relational database system. There are also database systems that are specifically designed to hold multidimensional data. These systems are typically called OLAP servers. Microsoft Analysis Server is an example of an OLAP server. The primary unit of data storage in a relational database system is a two-dimensional table. In an OLAP system the primary unit of storage is a multidimensional cube. Each cell of a cube holds the data for the intersection of a particular value for each of the cube s dimensions. The actual data storage for an OLAP system can be in a relational database system. Microsoft Analysis Services gives three data storage options MOLAP Multidimensional OLAP. Data and calculated aggregations stored in a multidimensional format. ROLAP Relational OLAP. Data and calculated aggregations stored in a relational database. HOLAP Hybrid OLAP. Data stored in a relational database and calculated aggregations stored in multidimensional format. Conclusion The importance of data transformation will continue to grow in the coming years as the usefulness of data becomes more apparent. DTS is a powerful and flexible tool for meeting your data transformation needs. The next chapter Using DTS to Move Data into a Data Mart describes the particular challenge of transforming relational data into a multidimensional structure for business analysis and OLAP. The rest of the book gives you the details of how to use DTS. Using DTS to Move Data into a Data Mart CHAPTER 4 IN THIS CHAPTER Multidimensional Data Modeling 78 The Fact Table 82 The Dimension Tables 84 Loading the Star Schema 88 Avoiding Updates to Dimension Tables 94 Getting Started with DTS 78 Part I With the introduction of OLAP Services in SQL Server Microsoft brought OLAP tools to a mass audience. This process continued in SQL Server 2000 with the upgraded OLAP .