delete column stats only

[slimdave]

begin
for x in (select column_name from user_tab_columns where table_name = 'MY_TABLE')
loop
DBMS_STATS.DELETE_COLUMN_STATS (
   ...
   colname => x.column_name,
   ...
   );
End Loop;
End;
/

It ain't follproof mind -- there is an implicit commit in the DBMS_STATS call, I expect, which could cause problems. Really you should load up the column names into a collection and loop through it.