The DBA_IND_COLUMNS view provides information about all columns included in indexes, on all tables in the database.

index_ownerTEXTUser name of the index’s owner.
schema_nameTEXTName of the schema in which the index belongs.
index_nameTEXTName of the index.
table_ownerTEXTUser name of the table’s owner.
table_nameTEXTName of the table in which the index belongs.
column_nameTEXTName of column or attribute of object column.
column_positionSMALLINTThe position of the column in the index.
column_lengthSMALLINTThe length of the column (in bytes).
char_lengthNUMERICThe length of the column (in characters).
descendCHARACTER(1)Always set to Y (descending); included for compatibility only.