SQL Server Integration Services: Difference between revisions

Revision as of 17:17, 15 December 2012

Revision as of 01:41, 16 December 2012

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'''SQL Server Integration Services''' ('''SSIS''') is a component of the [[Microsoft SQL Server]] database software that can be used to perform a broad range of [[data migration]] tasks.

'''SSIS''' is a platform for [[data integration]] and [[workflow application]]s. It features a fast and flexible [[data warehouse|data warehousing]] tool used for data extraction, transformation, and loading ([[Extract, transform, load|ETL]]). The tool may also be used to automate maintenance of SQL Server databases and updates to '''multid'''imensionalmultidimensional [[OLAP cube|cube data]].

'''First released with Microsoft SQL''' Server 2005, SSIS replaced [[Data Transformation Services]], which had been a feature of SQL Server since Version 7.0. '''Unlike DTS, which was include'''dincluded in all versions, SSIS is only available in the "Standard" and "Enterprise" editions.

=Features=

The '''S'''S'''IS'''SSIS Import/Export [[Wizard (software)|Wizard]] lets the user create packages that move data from a single data source to a destination with no transformations. The Wizard can quickly move data from a variety of source types to a variety of destination types, including text files and other SQL Server instances.

Developers tasked with creating or maintaining SSIS packages use a visual development tool based on [[Microsoft Visual Studio]] called the SQL Server [[Business Intelligence Development Studio]] (BIDS). It allows users to edit SSIS packages using a drag-and-drop user interface. A scripting environment in which to write programming code is also available in the tool. A package holds a variety of elements that define a workflow. Upon package execution, the tool provides color-coded, real-time monitoring.

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; Connections : A connection includes the information necessary to connect to a particular data source. Tasks can reference the connection by its name, allowing the details of the connection to be changed or configured at run time.

; Tasks : A task is an atomic work unit that performs some action. There are a couple of dozen tasks that ship in the box, ranging from the file system task (which can copy or move files) to the data transformation task. The data transformation task actually copies data; it implements the ETL features of the product

; Precedence constraints : Tasks are linked by precedence constraints. The precedence constraint preceding a particular task must be met before that task executes. The run time supports executing tasks in parallel if their precedence constraints so allow. '''Const'''raintsConstraints may otherwise allow different paths of execution depending on the success or failure of other tasks. Together with the tasks, precedence constraints comprise the '''workflow''' of the package.

; Event handlers : A workflow can be designed for a number of events in the different scopes where they might occur. In this way, tasks may be executed in response to happenings within the package —such as cleaning up after errors.

; Variables : Tasks may reference variables to store results, make decisions, or affect their configuration.

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* Row Sampling

The Conditional Split transformation is used to speed up the query on the source table based on a particular condition. It is similar to the "if..else" construct in the '''C''' language.

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