Default Secondary Index type for bins containing scalar values (i.e. integer, string).
Secondary index for bins containing ⇑Lists; The index will be built over the individual entries of the list.
SI for bins containing ⇑Maps; The index will be built over the individual keys of the map entries.
SI for bins containing ⇑Maps; The index will be built over the individual values of the map entries.
Specifies the collection datatype the secondary index should be built on. DEFAULT implies the value is not a collection datatype.z