Overall/Total Database Size
Select ( Select Sum(Bytes)/1024/1024/1024 Data_Size From Dba_Data_Files ) +
( Select Nvl(Sum(Bytes),0)/1024/1024/1024 Temp_Size From Dba_Temp_Files ) +
( Select Sum(Bytes)/1024/1024/1024 Redo_Size From Sys.V_$Log ) +
( SelectSum(Block_Size*File_Size_Blks)/1024/1024/1024 Controlfile_Size From V$Controlfile) “Size In Gb” From Dual;
Actual size of the Database in GB
Select Sum (Bytes) / 1024 / 1024 / 1024 As Gb From Dba_Data_Files;
