Datasheet

Chapter 1: Welcome to SQL Server Integration Services
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The SSIS runtime engine and its complementary programs actually run your SSIS packages. The engine
saves the layout of your packages and manages the logging, debugging, configuration, connections, and
transactions. Additionally, it manages handling your events when they are raised within your package.
The runtime executables provide the following functionality, which you ’ ll explore in more detail later
in this chapter:
Containers: Provide structure and scope to your package .
Tasks: Provide the functionality to your package .
Event handlers: Respond to raised events in your package .
Precedence constraints: Provide ordinal relationship between various items in your package .
In Chapter 3, you ’ ll spend a lot of time in each of these architectural sections, but the next few sections
provide a nice overview for the ones that are the most important.
Packages
A core component of SSIS and DTS is the notion of a package . A package best parallels an executable
program that maintains workflow and business logic. Essentially, a package is a collection of tasks
snapped together to execute in an orderly fashion. Precedence constraints are used to connect the
tasks together and manage the order in which tasks will execute, based on what happens in each task or
specialized rules. The package is compiled into a .DTSX file that is actually an XML - structured file with
collections of properties. Just like other .NET solutions, the file - based code is marked up using the
development environment and can then be saved and compiled for deployment to a SQL Server as a file
in the file system or can be saved into the msdb database metadata. The package XML structure stripped
down to the basic elements looks like this:
< ?xml version=”1.0”? >
< DTS:Executable xmlns:DTS=”www.microsoft.com/SqlServer/Dts”
DTS:ExecutableType=”MSDTS.Package.2” >
< DTS:ConnectionManager > < /DTS:ConnectionManager >
< DTS:PackageVariable > < /DTS:PackageVariable >
< DTS:Executable > < /DTS:Executable >
< DTS:Executable DTS:ExecutableType=”DTS.Pipeline.2” >
< components >
< component > < /component >
< /components >
< /DTS:Executable >
< DTS:EventHandler > < /DTS:EventHandler >
< DTS:PrecedenceConstraint > < /DTS:PrecedenceConstraint >
< DTS:Executable >
Here you can see the package collections of connections, package variables, executables, and precedence
constraints. The specific executable named
DTS.Pipeline.2 is a special task type that allows for
transformation of a data stream or pipeline that we ’ ll discover later. The point here is that the SSIS
package is an XML - structured file much like .RDL files are to Reporting Services. Of course, there
is much more to packages than that, but you ’ ll explore the other elements of packages, like event
handlers, later in this chapter.
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