V$INDEXED_FIXED_COLUMN displays the columns in dynamic performance tables that are indexed (X$ tables). The X$ tables can change without notice. Use this view only to write queries against fixed views (V$ views) more efficiently.
Name of the dynamic performance table that is indexed
Number that distinguishes to which index a column belongs
Name of the column that is being indexed
Position of the column in the index key (this is mostly relevant for multicolumn indexes)