Primary index is built on the field K, then KEY for relation is K and records are sorted on K.

Clustering index is built on the field K, then KEY for relation is X(X!=K) and records are sorted on K.

Atmost one Primary or clustering index is possible as data can be ordered only by 1 field.

Clustering index is built on the field K, then KEY for relation is X(X!=K) and records are sorted on K.

Atmost one Primary or clustering index is possible as data can be ordered only by 1 field.