Does SQL Server jump leaves when using a composite clustered index?

Question

Consider the following composite clustered index:

CREATE UNIQUE CLUSTERED INDEX ix_mytable ON mytable(a, b)

Obviously, a separate index on

Answer 1

No, there is no jumping over a clusters of 'a'. An index can be used only if the leftmost column is specified, otherwise a full scan needs to be employed.

Oracle has the so called 'Index Skip Scan' operator.