How do the differences between an operational database and a data warehouse effect the software and hardware requirements of each?(hard drives, Computer processors, main memory, backup devices, backup power supply and disaster recovery etc). Also, how do they effect the type of personnel that need to be hired for each?

Effects : on hard drives, Computer processors, main memory, backup devices, backup power supply and disaster recovery etc). If the company uses TERRADATA rather than other dbms for the DW, definitely it will effect the current ODS/OLTP which usually runs in oracle, sql server, db2 etc. Why? there would be an upgrade of your current hardware specs, plus the fulus, cha ching requirements. for the Personnel ? yep totally different idea from previous client/server developer, oltp developer, web developers. Training is required, offcourse it would be much easier to grasph the knowledge with the experienced programmers. Chuba Choo Choo