USER_IND_COLUMNS

COLUMNs comprising user's INDEXes and INDEXes on user's TABLES

Columns
   ___________________________
 
   INDEX_NAME
      Index name
   TABLE_NAME
      Table or cluster name 
   COLUMN_NAME
      Column name or attribute of object column
   COLUMN_POSITION
      Position of column or attribute within index
   COLUMN_LENGTH
      Maximum length of the column or attribute,in bytes
   CHAR_LENGTH
      Maximum length of the column or attribute,in characters
   DESCEND
      DESC if this column is sorted descending on disk,otherwise ASC

Related:

Simon Sheppard
SS64.com