Script to identify SQL generating Redo

SELECT when, sql, SUM(sx) executions, sum (sd) rows_processed 
FROM ( 
      SELECT to_char(begin_interval_time,’YYYY_MM_DD HH24′) when, 
             dbms_lob.substr(sql_text,4000,1) sql, 
             dhss.instance_number inst_id, 
             dhss.sql_id, 
             sum(executions_delta) exec_delta, 
             sum(rows_processed_delta) rows_proc_delta 
        FROM dba_hist_sqlstat dhss, 
             dba_hist_snapshot dhs, 
             dba_hist_sqltext dhst 
        WHERE upper(dhst.sql_text) LIKE ‘%Z_PLACENO%’ 
          AND ltrim(upper(dhst.sql_text)) NOT LIKE ‘SELECT%’
          AND dhss.snap_id=dhs.snap_id 
          AND dhss.instance_Number=dhs.instance_number 
          AND dhss.sql_id = dhst.sql_id  
          AND begin_interval_time BETWEEN to_date(’12-02-07 12:00′,’YY-MM-DD HH24:MI’)  
                                      AND to_date(’12-02-07 16:00′,’YY-MM-DD HH24:MI’) 
        GROUP BY to_char(begin_interval_time,’YYYY_MM_DD HH24′), 
            dbms_lob.substr(sql_text,4000,1), 
              dhss.instance_number, 
             dhss.sql_id 
) 
group by when, sql;