How to view storage configuration of Oracle database?

Problem:

You want to find out some indroductory information about the database.

Solution:

Every Oracle programmer/ DBA has at one point or another during their career inherited a database someone else have already set up.You needs to find out some introductory information about the database to learn more about it.

Idenitfy the host details and databsae version

Example

<p>SELECT instance_name,host_name,version,startup_time
FROM v$instance</p>

Output

<p>INSTANCE_NAME    HOST_NAME                      VERSION           STARTUP_TIME
TESTDB          ip-000-00-0-000                19.0.0.0.0        12/AUG/20</p>

Next, We will determine the tablespaces that make up the database

Example

<p>SELECT tablespace_name FROM dba_tablespaces ORDER BY tablespace_name;</p>

Output

<p>TABLESPACE_NAME
------------------------------
RDSADMIN
SYSAUX
SYSTEM
TEAM_DATA
TEAM_TEMP
TEAM_UNDO
TEMP
UNDOT1
USERS</p>

Next up, we will find about where the tablespaces data files reside on disk storage. In addition to the data files, we will also know where the temp files, control files, and online redo logs are located. All of this information is stored in different data dictionary views, but we can perform a UNION operation to put it all together.

Example

<p>SELECT 'DATA' as type,file_name,bytes FROM dba_data_files
UNION ALL
SELECT 'TEMP',file_name,bytes FROM dba_temp_files
UNION ALL
SELECT 'REDO',lf.member,l.bytes
FROM v$logfile lf join v$log l on lf.group#=l.group#
UNION ALL
SELECT 'CTL',value,NULL FROM v$parameter2 where name='control_files';</p>

We will look at the tablespace storage with below SQL.

Example

<p>SELECT f.tablespace_name,
  TO_CHAR(f.bytes,'99,999,999,999,999')                        AS allocated_bytes,
  NVL(TO_CHAR(se.bytes,'99,999,999,999,999'),LPAD('Empty',19)) AS used_bytes,
  TO_CHAR(NVL(TRUNC((se.bytes/f.bytes)*100,2),0),'990.00')     AS percent_used
FROM
  (SELECT df.tablespace_name,
    SUM(bytes) AS bytes
  FROM dba_data_files df
  GROUP BY df.tablespace_name
  ) f,
  (SELECT s.tablespace_name,
    SUM(bytes) AS bytes
  FROM dba_segments s
  GROUP BY s.tablespace_name
  ) se
WHERE f.tablespace_name=se.tablespace_name (+)
ORDER BY f.tablespace_name;</p>

Output

ADMIN                 7,340,032             131,072     1.78
SYSAUX            2,918,580,224       2,640,117,760    90.45
SYSTEM              629,145,600         565,772,288    89.92
TEAM_DATA             1,073,741,824               Empty     0.00
TEAM_UNDO             1,073,741,824           1,310,720     0.12
UNDOT1            1,038,090,240          74,186,752     7.14
USERS            15,714,156,544      10,962,141,184    69.75

Finally, we will idenitfy the users - oracle created users and non oracle created users.

SQL to list non-oracle users

<p>SELECT username,
  account_status,
  profile AS security_profile
FROM dba_users
WHERE oracle_maintained='N'
ORDER BY username;</p>

SQL to learn about the profiles

<p>SELECT resource_name,limit FROM dba_profiles WHERE profile='DEFAULT';</p>

Output

<p>CPU_PER_SESSION           UNLIMITED
CPU_PER_CALL                   UNLIMITED
LOGICAL_READS_PER_SESSION   UNLIMITED
LOGICAL_READS_PER_CALL       UNLIMITED
IDLE_TIME                       UNLIMITED
CONNECT_TIME                   UNLIMITED
PRIVATE_SGA                UNLIMITED
FAILED_LOGIN_ATTEMPTS        UNLIMITED
PASSWORD_LIFE_TIME            UNLIMITED
PASSWORD_REUSE_TIME           UNLIMITED
PASSWORD_REUSE_MAX            UNLIMITED
PASSWORD_VERIFY_FUNCTION         NULL
PASSWORD_LOCK_TIME            1
PASSWORD_GRACE_TIME           7
INACTIVE_ACCOUNT_TIME        UNLIMITED</p>