View POOL sizes in SGA

select pool, name , bytes from v$sgastat order by pool;

or

select pool, name, bytes from v$sgastat  select sum (value)/(1024*1024)
from v$parameter
where name in
  (
       'large_pool_size',
       'java_pool_size',
       'shared_pool_size'
   )
order by pool, name;

/*
select sum(bytes) from v$sgastat where pool = 'shared pool';

/* show parameter shared_pool
/*
select name,value
from v$parameter
where  upper(name) in ('DB_NAME','SGA_TARGET','DB_CACHE_SIZE','DB_BLOCK_SIZE','SGA_MAX_SIZE',
'SHARED_POOL_SIZE', 'LARGE_POO_SIZE');