Datasheet

❑ Row Count: Stores the row count from the data flow into a variable.
❑ Row Sampling: Captures a sampling of the data from the data flow by using a row count of the
total rows in the data flow.
❑ Script Component: Uses a script to transform the data. For example, you can use this to apply
specialized business logic to your data flow.
❑ Slowly Changing Dimension: Coordinates the conditional insert or update of data in a slowly
changing dimension. You’ll learn the definition of this term and study the process in Chapter 6.
❑ Sort: Sorts the data in the data flow by a given column.
❑ Term Extraction: Looks up a noun or adjective in text data.
❑ Term Lookup: Looks up terms extracted from text and references the value from a reference
table.
❑ Union All: Merges multiple data sets into a single data set.
❑ Unpivot: Unpivots the data from a non-normalized format to a relational format.
Error Handling and Logging
In SSIS, the package events are exposed in the user interface, with each event having the possibility of its
own event handler design surface. This design surface is the pane in Visual Studio where you can specify
a series of tasks to be performed if a given event happens. There are a multitude of event handlers to
help you develop packages that can self-fix problems. For example, the OnError error handler triggers
an event whenever an error occurs anywhere in scope. The scope can be the entire package or an indi-
vidual container. Event handlers are represented as a workflow, much like any other workflow in SSIS.
An ideal use for event handlers would be to notify an operator if any component fails inside the pack-
age. You’ll learn much more about event handlers in Chapter 13.
Handling errors in your data is easy now in SSIS 2005. In the data flow, you can specify in a transforma-
tion or connection what you wish to happen if an error exists in your data. You can select that the entire
transformation fails and exits upon an error, or the bad rows can be redirected to a failed data flow
branch. You can also choose to ignore any errors. An example of an error handler can be seen in Figure
1-8, where if an error occurs during the Derived Column transformation, it will be outputted to the data
flow. You can then use that outputted information to write to an output log.
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