MEMORY USED BY SQL STATEMENT

select machine,to_char(SQL_EXEC_START,'DD-MON-YY HH24:MI:SS')            runtime,
       pga_allocated 
  from dba_hist_active_sess_history 
 where sql_id = '&sql_id';


EXAMPLE OUTPUT:

MACHINE                   RUNTIME                 PGA_ALLOCATED

------------------------- -------------------- ----------------
MYPCNAME                  13-JUL-16 16:18:40        807,153,664
MYPCNAME                  13-JUL-16 16:18:40        329,003,008
MYPCNAME                  13-JUL-16 16:18:40        274,280,448
MYPCNAME                  13-JUL-16 16:18:40        215,887,872
MYPCNAME                  13-JUL-16 16:18:40        204,615,680

Top 10 - Biggest Tables and Indexes

Top 10 - Biggest Tables and Indexes

set lines 170
set pages 20
col owner      format a20
col object     format a30
col type       format a6
col tablespace format a20
col size_in_gb format 999,999.9
select * 
  from (select owner           owner,
               segment_name    object,
               segment_type    type,
               tablespace_name tablespace,
               round(bytes/1024/1024/1024,1) size_in_gb
          from dba_segments 
         where owner not in ('SYS','SYSTEM')
         order by bytes desc
       ) 
 where rownum < 11
 order by size_in_gb desc;