If you select Reset for a non-reusable Sequence Generator transformation, the Integration Service generates values based on the original start value each time it starts the session. Otherwise, the Integration Service updates the current value to reflect the last-generated value plus the increment value, and then uses the updated value the next time it uses the Sequence Generator transformation.
For example, you configure a Sequence Generator transformation to create values from 1 to 1,000 with an increment of 1. You choose reset to reset the start value to 1. During the first session run, the Integration Service generates numbers 1 through 234. In each subsequent mapping run, the Integration Service again generates numbers beginning with the initial value of 1.
If you do not reset, the Integration Service updates the current value to 235 at the end of the first run. The next time it uses the Sequence Generator transformation, the first value generated is 235.
Reset is disabled for reusable Sequence Generator transformations.