Database, table, and index definitions impact load performance.
FP_NBIT_AUTOSIZE_LIMIT limits the number of distinct values that load as NBit
FP_NBIT_LOOKUP_MB sets a threshold for the total NBit dictionary size
FP_NBIT_ROLLOVER_MAX_MB sets the dictionary size for implicit NBit rollovers from NBit to Flat FP
FP_NBIT_ENFORCE_LIMITS enforces NBit dictionary sizing limits. This option is OFF by default
Create all of the indexes you need before loading data. While you can always add new indexes later, it is much faster to load all indexes at once.