Reading alert log via SQL in Oracle 11g

X$DBGALERTEXT показывает последний log.xml

X$DIAG_ALERT_EXT показывает объединенное содержимое для файлов log_XX.xml, включая log.xml.

connect sys as sysdba

select * from X$DBGALERTEXT where rownum <= 20;


set linesize 254
col ORIGINATING_TIMESTAMP format a50
col MESSAGE_TEXT format a170

SELECT ORIGINATING_TIMESTAMP, message_text FROM X$DIAG_ALERT_EXT
where 1 = 1
  and originating_timestamp >= sysdate - 30
  and message_text like 'ALTER SYSTEM%'
  and message_text not like 'ALTER SYSTEM ARCHIVE LOG%'
;

Select ORA-XXXXX and TNS-XXXXX errors last 10 minutes:

set linesize 254
col ORIGINATING_TIMESTAMP format a50
col MESSAGE_TEXT format a170

SELECT inst_id, originating_timestamp, MESSAGE_TEXT
    FROM TABLE (
            gv$ (
               CURSOR (
                  SELECT inst_id, originating_timestamp, MESSAGE_TEXT
                    FROM v$diag_alert_ext
                   WHERE     originating_timestamp > (SYSDATE - 10/1440)
                         AND (MESSAGE_TEXT LIKE '%ORA-%' or MESSAGE_TEXT LIKE '%TNS-%')
                         AND MESSAGE_TEXT NOT LIKE '%TNS-12502%'
                      )
                )
               )
ORDER BY inst_id, originating_timestamp;

Shrinking temporary tablespace in Oracle 10g and 11g

Useful links

• Reclaiming Unused Space in Datafiles
• Temporary Tablespace Enhancements in Oracle Database 11g Release 1

Shrinking temporary tablespace in Oracle 10g

CREATE TEMPORARY TABLESPACE TEMP02 TEMPFILE 
  '/oracle/oradata/db/TEMP_02.dbf' SIZE 50M AUTOEXTEND ON;

ALTER DATABASE DEFAULT TEMPORARY TABLESPACE TEMP02;

Switch all existing users from old TEMP to new TEMP02 tablespace:

set serveroutput on
-- Switch all existing users to new temp tablespace.
BEGIN
  FOR cur_user IN (SELECT username FROM dba_users WHERE temporary_tablespace = 'TEMP') LOOP
    dbms_output.put_line('ALTER USER ' || cur_user.username || ' TEMPORARY TABLESPACE TEMP02');    
    EXECUTE IMMEDIATE 'ALTER USER ' || cur_user.username || ' TEMPORARY TABLESPACE TEMP02';
  END LOOP;
END;
/

Waiting for release old TEMP tablespace usage by applications/sessions:

lsof | grep temp01.dbf | wc -l
124

select count(*) from V$TEMPSEG_USAGE
where tablespace = 'TEMP';

  COUNT(*)
----------
        91

select tablespace, username, count(*)
  from V$TEMPSEG_USAGE
 where 1 = 1
   --and tablespace in ('TEMP', 'TEMP02')
   and tablespace = 'TEMP'
 group by tablespace, username;

when count become zero then drop unused old TEMP tablespace and files:

DROP TABLESPACE TEMP INCLUDING CONTENTS AND DATAFILES;

Recreate old TEMP tablespace and if you want switch back from TEMP02

CREATE TEMPORARY TABLESPACE TEMP TEMPFILE 
  '/oracle/oradata/db/TEMP_01.dbf' SIZE 50M AUTOEXTEND ON;

ALTER DATABASE DEFAULT TEMPORARY TABLESPACE TEMP;

Switch all existing users back to TEMP tablespace:

set serveroutput on
-- Switch all existing users to new temp tablespace.
BEGIN
  FOR cur_user IN (SELECT username FROM dba_users WHERE temporary_tablespace = 'TEMP02') LOOP
    dbms_output.put_line('ALTER USER ' || cur_user.username || ' TEMPORARY TABLESPACE TEMP');    
    EXECUTE IMMEDIATE 'ALTER USER ' || cur_user.username || ' TEMPORARY TABLESPACE TEMP';
  END LOOP;
END;
/

Waiting for release TEMP02 tablespace usage by applications/sessions:

lsof | grep temp02.dbf | wc -l
124

select count(*) from V$TEMPSEG_USAGE
where tablespace = 'TEMP02';

  COUNT(*)
----------
        91

select tablespace, username, count(*)
  from V$TEMPSEG_USAGE
 where 1 = 1
   --and tablespace in ('TEMP', 'TEMP02')
   and tablespace = 'TEMP02'
 group by tablespace, username;

when count become zero then drop unused TEMP02 tablespace and files:

DROP TABLESPACE TEMP02 INCLUDING CONTENTS AND DATAFILES;

Temporary Tablespace Enhancements in Oracle Database 11g

alter tablespace temp shrink space [keep 100m];

The shrink can also be directed to a specific tempfile using the TEMPFILE clause.

ALTER TABLESPACE temp SHRINK TEMPFILE '/oracle/oradata/db/temp01.dbf' KEEP 30M;

View V$TEMPSEG_USAGE

lsof | grep temp01.dbf | wc -l
124

select * from V$TEMPSEG_USAGE

select count(*)
  from V$TEMPSEG_USAGE
 where tablespace = 'TEMP';

select tablespace, username, count(*)
  from V$TEMPSEG_USAGE
 where 1 = 1
   --and tablespace in ('TEMP', 'TEMP02')
   --and tablespace = 'TEMP'
 group by tablespace, username;

Issue: Shrinking of Temp Tablespace does not take effect

Run this query to find if there are any sessions using your temp tablespace a long time:

SELECT se.username username,
       se.SID sid, se.serial# serial#,
       se.status status,
       'alter system kill session ''' || se.sid || ',' || se.serial# || ''' immediate;' kill_session_cmd,
       se.sql_hash_value, se.sql_id,
       se.prev_hash_value,se.machine machine,
       su.TABLESPACE tablespace,su.segtype,
       su.CONTENTS CONTENTS
  FROM v$session se,
       v$tempseg_usage su /* v$sort_usage */
 WHERE se.saddr=su.session_addr
   AND status = 'ACTIVE'
;

Check if you can drop those sessions and then try shrink. Or you can create a new tablespace move every user to that temp tablespace and than drop this old one.

Move Flash Recovery Area to a new location

For to accomplish moving flash recovery area:

1. Change the value of the DB_RECOVERY_FILE_DEST initialization parameter to a new value.
2. Shut down the instance.
3. Start up the instance and mount the database.
4. Execute the ALTER DATABASE FLASHBACK OFF command.
5. Execute the ALTER DATABASE FLASHBACK ON command.
6. Open the database.

SQL> ALTER SYSTEM SET DB_RECOVERY_FILE_DEST= '/u01/oradata/flash';

SQL>  SHUTDOWN IMMEDIATE;

SQL> STARTUP MOUNT;

SQL> ALTER DATABASE FLASHBACK OFF;

SQL> ALTER DATABASE FLASHBACK ON;

SQL> ALTER DATABASE OPEN;

Use Data Recovery Advisor to Perform Recovery

rman target /
LIST FAILURE;
LIST FAILURE 182 DETAIL;
ADVISE FAILURE;
REPAIR FAILURE;

• LIST FAILURE - to show information about the failures.
• ADVISE FAILURE - to obtain a report of your repair options.
• Finally, REPAIR FAILURE will fix the problem.

Запретить пользователям подключаться в базе

RESTRICTED_SESSION_CLAUSE

ENABLE

Specify ENABLE to allow only users with RESTRICTED SESSION system privilege to log on to Oracle Database. Existing sessions are not terminated.

alter system enable restricted session;

select logins from v$instance;

LOGINS
----------
RESTRICTED

DISABLE

Specify DISABLE to reverse the effect of the ENABLE RESTRICTED SESSION clause, allowing all users with CREATE SESSION system privilege to log on to Oracle Database. This is the default.

alter system disable restricted session;

select logins from v$instance;

LOGINS
----------
ALLOWED