How to use dbms_stats.report_col_usage

set long 10000
select dbms_stats.report_col_usage('SALES', 'ORDERS') from dual;
exit

Output could look something like this:

DBMS_STATS.REPORT_COL_USAGE('SALES','ORDERS')
--------------------------------------------------------------------------------
LEGEND:
.......

EQ         : Used in single table EQuality predicate
RANGE      : Used in single table RANGE predicate
LIKE       : Used in single table LIKE predicate
NULL       : Used in single table is (not) NULL predicate
EQ_JOIN    : Used in EQuality JOIN predicate
NONEQ_JOIN : Used in NON EQuality JOIN predicate
FILTER     : Used in single table FILTER predicate
JOIN       : Used in JOIN predicate

DBMS_STATS.REPORT_COL_USAGE('SALES','ORDERS')
--------------------------------------------------------------------------------
GROUP_BY   : Used in GROUP BY expression
...............................................................................

###############################################################################

COLUMN USAGE REPORT FOR SALES.ORDERS
.......................................................

1. ORDER_DATE                          : EQ RANGE
2. ORDER_ID                            : EQ
3. ITEM_NAME                           : EQ
###############################################################################

This makes it easy to see which columns could benefit from an index.