When using any RDBMS there exist a distinct difference between the actual size of the data and the physical size of the database. The physical size on disk is defined as the space required for the database to operate (also known as the “foot print”). This article will discuss the components which make up the physical size of the database and how to determine that size within Oracle. NOTE: This does not include determining of OS layer database objects (Control Files, Binaries, Log Files, and Trace files ).

Components which make-up the physical size of an Oracle database:
1. Data Files
2. Temporary Files
3. Redo Logs
4. Archive log Files

1. Logon to your Oracle database server as the Oracle software owner.

2. Logon to SQLPLUS with SYSDBA privileges.

mylinux:> sqlplus ‘/ as sysdba’

SQL>

3. Execute the following SQL to get the size of all Data files: select
sum(bytes)/1024/1024 from dba_data_files;

SQL> select sum(bytes)/1024/1024 from dba_data_files;

SQL>

4. Execute the following SQL to get the size of all Temporary files: select sum(bytes)/1024/1024 from dba_temp_files;

SQL> select sum(bytes)/1024/1024 from dba_temp_files;

SQL>

5. Execute the following SQL to get the size of all redo logs: select
sum(bytes)/1024/1024 from v$log;

SQL> select sum(bytes)/1024/1024 from v$log;

SQL>

6. Execute the following SQL to get the size of all archive redo logs: select sum(block_size*blocks)/1024/1024 from v$archived_log;

SQL> select sum(block_size*blocks)/1024/1024 from v$archived_log;

SQL>

7. This completes the physical size of an Oracle database.

Larry Catt, OCP 9i, 10g
oracle@allcompute.com
www.allcompute.com