A Vector index can be created on an X100 table which has one or more columns of type Vector with a single-precision float coordinate type, and which has a single-column integer primary key.

The presence of a Vector index can improve the performance of nearest-neighbour queries which ORDER BY the result of a Vector_DISTANCE() call between a Vector-typed column and a constant Vector value, and which use FETCH APPROX FIRST <n> ROWS ONLY.