Flags

Ascending

Check this box to set the collating sequence of the segment in ascending order. Otherwise, the index will be set in descending order.

Unique

Check this box to indicate that the segment is unique. The primary index must be unique. This parameter is meaningful only for single-segment keys or the first segment of a concatenated index.

Business Math

Check this box to indicate that the segment uses business math sorting or if a column of this type is specified as an index. Leaving the box unchecked defines alphabetic rather than numeric sorting.