Check maximum memory utilization for oracle Database

Check maximum memory utilization for oracle Database

-- SGA + PGA is best not to exceed 70% of the total memory

on linux
$ free -g
             total       used       free     shared    buffers     cached
Mem:            11         11          0          0          0          4
-/+ buffers/cache:          6          4
Swap:           13          0         12

--check the utilization of all the components
COLUMN name FORMAT A30
COLUMN value FORMAT A10
SELECT name, value /1024/1024
FROM   v$parameter
WHERE  name IN ('pga_aggregate_target', 'sga_target','memory_target')
UNION
SELECT 'maximum PGA allocated' AS name, TO_CHAR(value)/1024/1024 AS value
FROM   v$pgastat
WHERE  name = 'maximum PGA allocated';

--check the utilization of all the components of memory
select component ,CURRENT_SIZE/1024/1024 "CURRENT_SIZE in MB"  ,MIN_SIZE/1024/1024          
     ,MAX_SIZE/1024/1024 "MAX_SIZE in MB"          ,USER_SPECIFIED_SIZE/1024/1024 "USER_SPECIFIED_SIZE in MB", LAST_OPER_TYPE 
from v$memory_dynamic_components
where component in ('SGA Target','PGA Target');

--check the utilization of SGA
     col  COMPONENT            format a30
     col  CURRENT_SIZE         format 99999999999
     col  MIN_SIZE             format 99999999999
     col  MAX_SIZE             format 99999999999
     col  USER_SPECIFIED_SIZE  format 99999999999
     col  LAST_OPER_TYPE       format a15
     select inst_id,
     COMPONENT          ,
     CURRENT_SIZE/1024/1024 "CURRENT_SIZE in MB"  ,
     MIN_SIZE/1024/1024          
     ,MAX_SIZE/1024/1024 "MAX_SIZE in MB"  ,
    USER_SPECIFIED_SIZE/1024/1024 "USER_SPECIFIED_SIZE in MB", 
    LAST_OPER_TYPE    
from gv$sga_dynamic_components 
where component in ('shared pool','large pool','java pool','streams pool','DEFAULT buffer cache');