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Microsoft SQL Server 2008 R2 Unleashed- P224:SQL Server 2005 provided a number of significant new features and enhancements over what was available in SQL Server 2000. This is not too surprising considering there was a five-year gap between these major releases.Microsoft SQL Server 2008 is not as much of a quantum leap forward from SQL Server 2005 | 2194 CHAPTER 53 SQL Server 2008 Reporting Services field names field data types collation case sensitivity and so on . Datasets also store the underlying query used to derive report data from a data source and are aware of any parameters needed to obtain that data for example in cases where the underlying data source is a stored procedure. Every data-bound control on your report needs a dataset from which it will be populated at report and query execution time. In BIDS datasets are listed in the Report Data window s tree listing and after you create a dataset you can simply drag its fields from the tree onto the appropriate drop zones of your data-bound controls to create a link between the two. In simple terms this means that for every row your query returns an instance of that field is repeated in the data-bound control. This description is of course an oversimplification you can slice and dice your data in many other ways as you ll soon see. Using Shared Datasets New to SSRS 2008 R2 shared datasets further improve the decoupling of report data from reports. They also encourage reuse and accelerate report execution. A shared dataset is simply a dataset you define at design time that can then be reused by any number of reports. You may modify or delete a shared dataset independently of any reports or report parts that depend on it and vice versa. Using shared datasets prevents the need for recreating the same dataset in multiple reports. Redundancy is the enemy of maintainable code and using shared datasets prevents you from letting small differences in your underlying queries produce inconsistent results something end users tend to intensely dislike . Like regular datasets shared datasets may make use of input parameters. At execution time shared dataset output is cached according to unique combinations of parameter input much like SQL Server stored procedures . This leads to efficiency gains at report execution time. Like reports and other SSRS objects shared .
