1. Here is the query to find out the total file size of a Oracle
database
select
b.name,
(
select sum(bytes)/1024/1024/1024 DF_size from dba_data_files ) +
(
select nvl(sum(bytes),0)/1024/1024/1024 TF_size from dba_temp_files ) +
(
select sum(bytes)/1024/1024/1024 RLF_size from sys.v_$log ) +