You are creating a SQL Server Integration Services (SSIS) package that implements a Type
3 Slowly Changing Dimension (SCD).
You need to add a task or component to the package that allows you to implement the SCD
logic.
What should you use?
A.
a Script component
B.
an SCD component
C.
an Aggregate component
D.
a Merge component
D
Hmm… I don’t understand how a merge can do this? I thought it was just joins datasets. I think the answer is A as you could implement the type 3 scd manually via a script.
I was wondering why D was correct at first and actually It is correct. In Merge component you can add another column and pass the value from merge input 1 to it as “old” and set the column from merge input 2 to the current column. And then we actually have the previous and current values in the pipeline.
this is a tricky question: yes, you can add another column and save “current” and “old” values in the pipline with a “Merge” component, but the values will be in a different rows, and having SCD3 we have to group them by KeyID, to have KeyID, Value, Value_old structure
Snail is right.
But why couldn’t we use an SCD-componten?
https://msdn.microsoft.com/en-us/library/ms141715.aspx
Or is this a trick question. Does such a component not exist? Is the SCD-transformation not a component and do we only have an SCD-wizard instead, which isn’t a component?
Or is this the trick: “The Slowly Changing Dimension Wizard only supports connections to SQL Server.” Since the question doesn’t mention the source, we shouldn’t restrict ourselves to SQL Server?
Merge in sissy works like a union all so you cannot incline the type 3 scud with it.
You should youse look-up. But as it is not mentioned, what is left is a script component
Or a t SQL merge ( in sissy merge join)