Oracle DB, purge large tables

I have a huge table WLI_NESOA2_REPORTING_ARCHIVE and I need to purge 10000 rows at a time for all records older than 2013-05-10. It's easy if you use a ROWID table and empty it progressively.

--evaluate number of rows to delete
select count(*) from WLI_NESOA2_REPORTING_ARCHIVE;
select count(*) from WLI_NESOA2_REPORTING_ARCHIVE where EventOccuredOn < '2013-05-10';

--prepare empty table containing those rowids
drop table tobedeleted;

--populate table
create table tobedeleted  as SELECT rowid as MYROWID from WLI_NESOA2_REPORTING_ARCHIVE where EventOccuredOn < '2013-05-10';

--evaluate if numbers match
select count(*) from tobedeleted;


DECLARE
  nCount  NUMBER; 
BEGIN
  nCount := 0;
  LOOP
    --create subset of 10000 to delete
    execute immediate 'create table TOBEDELETEDNOW as select MYROWID from tobedeleted where rownum <= 10000';
    --delete first 10000
    execute immediate 'delete from WLI_NESOA2_REPORTING_ARCHIVE where rowid in (select MYROWID from TOBEDELETEDNOW )';
    commit;
    --remove the already purged records from list
    execute immediate 'delete from tobedeleted where MYROWID in (select MYROWID from TOBEDELETEDNOW)';
    nCount := sql%rowcount;
    execute immediate 'drop table TOBEDELETEDNOW';
    commit;


    DBMS_OUTPUT.PUT_LINE('deleted records: ' || to_char(ncount) );
    commit;    

    EXIT WHEN nCount = 0;

  END LOOP;
end;
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