One of the important benefits of client/server architecture is the ability of database servers to quickly and efficiently produce summaries of large amounts of data and send small result sets to client applications. In this appendix, you will learn how to use the features of SQL Server that allow you to create queries that summarize data.
Generally, summarizing data with SQL statements is too slow and not flexible enough for querying data in a data warehouse. This is why data warehouse data is further processed into OLAP cubes. Using SQL to summarize data is nevertheless an important technique to use when transforming source data into the data warehouse database.
To complete the lessons in this appendix, you must