Some comments :

a) your affirmation "using parallel 8 which will ** of course ** reduce the index creation time..." is NOT necessarily true : see, parallel means "I have unused resources at the moment (CPUs, memory, I/O bandwith) , and I want to have various processes doing a part of the big job each one". OF COURSE, each process WILL consume CPU, RAM & I/O, *** so *** if right now you DON´T have available resources in the machine, having even MORE processes running WILL slow you in a BIG way.

b) yes, it is safe to do it in production, I always do using PARALLEL (and NOLOGGING, for the matter) , no probs.

Regards,

Chiappa