Merge and Union All transformation components are used to join data in the pipeline. This data may come from more than one source, or have been divided previously in the pipeline. The main reason we use these components is to avoid duplicate work in the pipeline because the data at this point forward has the same treatment.
The main differences between the two components are that Merge component requires input data sorted and it's not possible to have more than two inputs. There are sufficient reasons from consider this Merge component useless.
To get ready for this recipe, use the following steps:
Open SQL Server Data Tools (SSDT) and create a new SSIS project.
Provide a name and a location for the SSIS project and proceed.
Select the package created by default and rename it to
P01_UnionData.dtsx
.