compression - order by matters

You get much better compress if you order the data as you compress
use this sql to work out the best order by clause


SELECT
', ' || dtc.column_name
, dtc.num_distinct
, dtc.avg_col_len
FROM dba_tab_cols dtc
WHERE dtc.owner = 'OWNER'
AND dtc.table_name = 'TABLE_TO_COMRESS'
ORDER BY
dtc.num_distinct
,dtc.avg_col_len DESC;