Differences between Merge and Union All transformations in SSIS
S.NoMergeUnion All1Number of inputs allowed:
Merge transformation can accept only two inputs.Number of inputs allowed:
Union all can take more than two inputs.
2Data to be sorted or not before Merge transformation:
Data has to be sorted before Merge Transformation.Data to be sorted or not before Union All transformation:
Union all does not have any condition like Merge.