---查看shared_pool使用情况 
column shared_pool_used format 9,999.99
column shared_pool_size format 9,999.99
column shared_pool_avail format 9,999.99
column shared_pool_pct format 999.99

select
       shared_pool_used,
       (shared_pool_used/shared_pool_size)*100  Shared_pool_per,
       shared_pool_size,
       (shared_pool_size-shared_pool_used) shared_pool_avail from
(
select
  sum(a.bytes)/(1024*1024) shared_pool_used
  from v$sgastat a
where a.name in
  ( 'table definiti',
  'dictionary cache',
  'library cache',
  'sql area',
  'PL/SQL DIANA')
),
(
select
  sum(b.bytes)/(1024*1024) shared_pool_size
from v$sgastat b
where pool='shared pool'
);