Decision Support Services

SQL Server also provides decision support facilities. This facility is known as data warehousing or business intelligence. Decision support, analysis support the user at the database information.

Decision support system database is implemented as a separate duplicate information and read-only and stored in another operating system, and is usually called a data mart or data warehouse. Some reasons for the decision support system separate databases :

1. Decision support activities can be located on a separate database server so that even the integrity and operational databases performance undisturbed.
2. Operational database structure is usually very complicated and optimized for the transaction.
3. Decision support database must declare the consolidation of a number of operating system databases, operating systems, and different hardware platforms.

The data did not suddenly appear in a decision support database. Such data must be moved periodically. Before the transfer of data should be validated, cleaned, and in the transformation. This process is called extraction and transformation. SQL Server has a facility called Data Transformation Services (DTS) to conduct a population of decision support database. With DTS, you can create a routine to extract data from a number of operating systems using OLE DB or ODBC, perform data validation and transformation, and then call him at high speed into a decision support database.

Usually, decision support databases are redundant, because it is a copy of the operational database, thus requiring periodic maintenance involving large amounts of data. Query processor of SQL Server provides a number of techniques called bulk processing updates that are designed to improve the performance of operations serve targeted. For example, when changing large amounts of data, the query processor will try to save all changes to the index that are affected in a pass if possible. This method is faster than by changing the index by way of line by line.

SQL Server also contains a number of tools to write queries in natural language. This tool is called English Query. You can use this facility to create a description of the entry and relationships expressed in a database.