Query to find Total Size & Free size of SGA

SQL> select sum(value)/1024/1024/1024 "TOTAL SGA (GB)" from v$sga;

TOTAL SGA (GB)
--------------------------
    25.5105934



SQL> select sum(bytes)/1024/1024/1024 " GB" from v$sgastat where name!='free memory';

        GB
----------------
 14.027292


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