select name,total,round(total-free,2) used, round(free,2) free,round((total-free)/total*100,2) pctused from
(select 'SGA' name,(select sum(value/1024/1024) from v$sga) total,
(select sum(bytes/1024/1024) from v$sgastat where name='free memory')free from dual)
union
select name,total,round(used,2)used,round(total-used,2)free,round(used/total*100,2)pctused from (
select 'PGA' name,(select value/1024/1024 total from v$pgastat where name='aggregate PGA target parameter')total,
(select value/1024/1024 used from v$pgastat where name='total PGA allocated')used from dual);