i often ran into a situation to rebuild large indices (approx. 4GB) -and sometimes i ran into ora-01652.

TBS is 6GB overall, 3.7GB are used, TEMP is about 7.6GB, 3GB are used.

my question is how to determine in general a percentage of free space (e.g. 50%) to 'alter index rebuild' or a decision to prefer to drop and re-create them ?

thanks in advance