Cluster is not suitable for heavy updated tables.

If the column used in bit map index is updated frequently, then you will experience heavy lock on the table. This will hurt performance.

IOT is the best choice.

You can cache the small tables in buffer pool keep area to get good performance. Also think of partitioning the big table, Parallel Query Option, etc.

Every system is unique. After loading data, post your Query here. We may suggest to improve the query performance.