V$INDEXED_FIXED_COLUMN

This view displays the columns in dynamic performance tables that are indexed (X$ tables). The X$ tables can change without notice. Use this view only to write queries against fixed views (V$ views) more efficiently.

Column	Datatype	Description
TABLE_NAME	VARCHAR2(30)	The name of the dynamic performance table that is indexed
INDEX_NUMBER	NUMBER	Number that distinguishes to which index a column belongs
COLUMN_NAME	VARCHAR2(30)	Name of the column that is being indexed
COLUMN_POSITION	NUMBER	Position of the column in the index key (this is mostly relevant for multicolumn indexes)