SQL Server 2005 Integration Services Architecture

SQL Server 2005 Integration Services consists of a core run-time engine and other executable components to support extract, transform, and load (ETL) processes.

Integration Services’ core component, the run-time engine, controls the ETL process workflow (referred to as control-flow in Integration Services language)—that is, the logical steps in the ETL process and the sequence of those steps. The engine runs one or more control-flow tasks, which are executable objects that encapsulate the units of work in the workflow (which might include, for instance, moving or copying files or sending SQL Server commands to a database). Tasks can be further organized in containers, which encapsulate one or more tasks and provide capabilities such as loops and branches (a container could loop over a task some specified number of times, for instance). During execution, tasks and containers issue events (for example, containers and tasks issue events when they complete or if they fail), which are handled by event handlers.