By default, Adaptive Server uses slow bcp by default if a table has a clustered index, index, or trigger with the select into/bulk copy enabled.
For slow bulk-copy:
You do not have to set select into/bulkcopy.
Rules are not enforced and triggers are not fired, but defaults are enforced.
All data changes are logged, as are page allocations.
Indexes are updated as rows are copied in, and index changes are logged.