set termout off feedback off verify off linesize 200

select snap_id,to_char(begin_time,'DD-MON-YY HH24') Time,metric_name,maxval/1024/1024 Name from dba_hist_sysmetric_summary
where metric_name ='Total PGA Allocated' and instance_number=&1 and snap_id between &2 and &3;
/