Hash Clusters

We are designing our first Oracle application which is an Information Warehouse of 70 odd tables. The application will be read only; we will be loading the data on a monthly data. Someone suggested to me that perhaps we should consider hash clusters for some of the tables since they are read only. From a course I took, it was suggested that hash clusters shuld only be used if you have a huge table with a static number of keys (eg. 10,000 hashkeys). Would this application really be considered static since we are loading the data on a regular basis. If we created hash clusters on some of the tables, would we have to recreate the cluster whenever we load the table and if so, would this be a lengthy process?.

-- 
Rosemary Fleming 
Database Administration 
Toronto Dominion Bank 
The opinions expressed here may not necessarily be those of my employer.