Which segments are above the HWM in a tablespace ?

https://jonathanlewis.wordpress.com/tablespace-hwm/

Simple shell script to purge WRH\$_SQL_PLAN until a specified date and reclaim space on SYSAUX tablespace

nbparam=$#

case $nbparam in
      0) echo "Usage = sh purge_sql_plan.sh <until_date>"
         exit 1;;
      *);;
   esac

export date=$1

sqlplus 'CONN_STRING' <<aa
set echo on timing on
DECLARE
   min_date   DATE;
BEGIN
   SELECT MIN (timestamp) INTO min_date FROM SYS.WRH\$_SQL_PLAN;

   WHILE min_date < TO_DATE ('$date', 'DD/MM/YYYY')
   LOOP
      DBMS_OUTPUT.put_line ('Date : ' || min_date);

      DELETE FROM SYS.WRH\$_SQL_PLAN
            WHERE timestamp <= min_date;

      COMMIT;
      min_date := min_date + 1;
   END LOOP;
END;
/

ALTER TABLE SYS.WRH\$_SQL_PLAN move parallel tablespace sysaux;
ALTER TABLE SYS.WRH\$_SQL_PLAN noparallel;
alter index SYS.WRH\$_SQL_PLAN_PK rebuild parallel;
alter index SYS.WRH\$_SQL_PLAN_PK noparallel;

exit;
aa