Query to find the memory of database in oracle,sql

Question

Hi All,
Please let me know the query to find the memory of database in oracle,sql.
Thanks,
sajith

Answer 1

How do I find the overall database size?
The biggest portion of a database's size comes from the datafiles. To find out how many megabytes are allocated to ALL datafiles:
select sum(bytes)/1024/1024 "Meg" from dba_data_files;
To get the size of all TEMP files:
select nvl(sum(bytes),0)/1024/1024 "Meg" from dba_temp_files;
To get the size of the on-line redo-logs:
select sum(bytes)/1024/1024 "Meg" from sys.v_$log;
Putting it all together into a single query:
select a.data_size+b.temp_size+c.redo_size "total_size"
from ( select sum(bytes) data_size
from dba_data_files ) a,
( select nvl(sum(bytes),0) temp_size
from dba_temp_files ) b,
( select sum(bytes) redo_size
from sys.v_$log ) c;
Another query ("Free space" reports data files free space):
col "Database Size" format a20
col "Free space" format a20
select round(sum(used.bytes) / 1024 / 1024 ) || ' MB' "Database Size"
, round(free.p / 1024 / 1024) || ' MB' "Free space"
from (select bytes from v$datafile
union all
select bytes from v$tempfile
union all
select bytes from v$log) used
, (select sum(bytes) as p from dba_free_space) free
group by free.p
This is what I use :P From http://www.orafaq.com/wiki/Oracle_database_FAQ#How_do_I_find_the_overall_database_size.3F