Some usefull TIPS

==Script to Report Frequency of Log Switches ==

REM LOCATION:   Object Management\Redo Logs
REM FUNCTION:   Provide data on Redo Log Switches
REM TESTED ON:  10.2.0.3, 11.1.0.6
REM PLATFORM:   non-specific
REM REQUIRES:   v$thread
REM
REM  This is a part of the Knowledge Xpert for Oracle Administration library.
REM  Copyright (C) 2008 Quest Software
REM  All rights reserved.
REM
REM ******************** Knowledge Xpert for Oracle Administration ********************
COLUMN avg_log_switch_min format 9,999.99 heading "Average|Log|Switch|Times|(Min)"

SET lines 132 pages 60 feedback off verify off echo off
TTITLE 'Average Log Switch Time Report'
PROMPT  'Note that high rates of Redo Log switching can cause performance problems'
PROMPT 'If this report indicates average switch times of less than 10 minutes'
PROMPT 'you should consider increasing the size of your redo logs.'

WITH redo_log_switch_times AS
     (SELECT   sequence#, first_time,
               LAG (first_time, 1) OVER (ORDER BY first_time) AS LAG,
                 first_time
               - LAG (first_time, 1) OVER (ORDER BY first_time) lag_time,
                 1440
               * (first_time - LAG (first_time, 1) OVER (ORDER BY first_time)
                 ) lag_time_pct_mins
          FROM v$log_history
      ORDER BY sequence#)
SELECT AVG (lag_time_pct_mins) avg_log_switch_min
  FROM redo_log_switch_times;

USER idle time

SELECT sid, osuser, username, status,
TO_CHAR(logon_time, 'DAY HH24:MI:SS') LOGON_TIME,
FLOOR(last_call_et/3600)||':'||
FLOOR(MOD(last_call_et,3600)/60)||':'||
MOD(MOD(last_call_et,3600),60) IDLE, program
FROM v_$session
WHERE username IS NOT NULL
ORDER BY last_call_et;

USER temp tablespace

SELECT username, default_tablespace, temporary_tablespace
FROM dba_users
ORDER BY 1;

USER informations

SELECT u.username, u.default_tablespace, 
u.temporary_tablespace "TMP TBS", u.profile, r.granted_role,
r.admin_option, r.default_role
FROM sys.dba_users u, sys.dba_role_privs r
WHERE u.username = r.grantee (+)
GROUP BY u.username, u.default_tablespace,
u.temporary_tablespace, u.profile, r.granted_role,
r.admin_option, r.default_role;

Create user sample

CREATE USER username
IDENTIFIED BY password
DEFAULT TABLESPACE tablespacename
TEMPORARY SPACE temp_tablespacename
QUOTA UNLIMITED ON tablespacename; 

GRANT CONNECT TO username;
GRANT RESOURCE TO username;

Active Processes(DBA)

SET pagesize 55;
SET linesize 170;
col SQL format a80;
col SERVER heading 'SVR' format a3;
col EVENT heading 'WAITING' format a30 fold_after;
col OSUSER heading 'OSUSER' format a8;
col USERNAME heading 'USERNAME' format a8;
col PID heading 'OSPID' format 99999;
col DISK_READS heading 'DISK I/O' format 99999999;
col BUFFER_GETS heading 'BUFFER|GETS' format 99999999;
 
SELECT  SUBSTR(V$SESSION.USERNAME,1,8) USERNAME,
     V$SESSION.OSUSER OSUSER,
--        DECODE(V$SESSION.SERVER,'DEDICATED','D','SHARED','S','O') SERVER,
     V$SQLAREA.DISK_READS DISK_READS,
     V$SQLAREA.BUFFER_GETS BUFFER_GETS,
        SUBSTR(V$SESSION.LOCKWAIT,1,10) LOCKWAIT,
     V$SESSION.PROCESS PID,
     V$SESSION_WAIT.EVENT EVENT,
        V$SQLAREA.SQL_TEXT SQL
FROM    V$SESSION_WAIT, V$SQLAREA, V$SESSION
WHERE   V$SESSION.SQL_ADDRESS = V$SQLAREA.ADDRESS AND
     V$SESSION.SQL_HASH_VALUE = V$SQLAREA.HASH_VALUE AND
        V$SESSION.SID = V$SESSION_WAIT.SID (+) AND
     V$SESSION.STATUS = 'ACTIVE' AND
     V$SESSION_WAIT.EVENT != 'client message'
ORDER BY V$SESSION.LOCKWAIT ASC, V$SESSION.USERNAME;

Kill Session

• Identify the Session to be Killed

SET LINESIZE 100
COLUMN spid FORMAT A10
COLUMN username FORMAT A10
COLUMN program FORMAT A45

SELECT s.inst_id,
s.sid,
s.serial#,
p.spid,
s.username,
s.program
FROM   gv$session s
JOIN gv$process p ON p.addr = s.paddr AND p.inst_id = s.inst_id
WHERE  s.type != 'BACKGROUND';

SELECT SID, SERIAL# FROM V$SESSION WHERE USERNAME = 'LSHR';

• kill session

  https://oracle-base.com/articles/misc/killing-oracle-sessions

 The basic syntax for killing a session is shown below.

 SQL> ALTER SYSTEM KILL SESSION 'sid,serial#';

ALTER SYSTEM KILL SESSION '7,15';

 In a RAC environment, you optionally specify the INST_ID, shown when querying the GV$SESSION view. This allows you to kill a session on different RAC node.

 SQL> ALTER SYSTEM KILL SESSION 'sid,serial#,@inst_id';

Show dead case

SELECT distinct KTUXECFL,count(*) from x$ktuxe group by KTUXECFL;

How to see the oldest flashback available?

Using the following query one can see the flashback data available.

SELECT to_char(sysdate,'YYYY-MM-DD HH24:MI') current_time, to_char(f.oldest_flashback_time, 'YYYY-MM-DD HH24:MI') OLDEST_FLASHBACK_TIME,
(sysdate – f.oldest_flashback_time)*24*60 HIST_MIN FROM v$database d, V$FLASHBACK_DATABASE_LOG f;

List Earliest Flashback Database Time and SCN

--
-- List Earliest Flashback Database Time and SCN.
--
 
SET PAUSE ON
SET PAUSE 'Press Return to Continue'
SET PAGESIZE 60
SET LINESIZE 300
SET VERIFY OFF
 
COLUMN oldest_flash_scn FOR 999,999,999
 
ALTER SESSION 
   SET nls_date_format='DD MON YYYY hh24:mi:ss'
/
 
SELECT 
   oldest_flashback_scn,
   oldest_flashback_time
FROM  
   v$flashback_database_log
/

List Flashback Database Restore Points

Oracle Database » SQL Library » List Flashback Database Restore Points

--
-- List Flashback Database Restore Points
--
 
SET PAUSE ON
SET PAUSE 'Press Return to Continue'
SET PAGESIZE 60
SET LINESIZE 300
SET VERIFY OFF
 
COLUMN scn FOR 999,999,999,999,999
COLUMN Incar FOR 99
COLUMN name FOR A25
COLUMN storage_size FOR 999,999,999,999
COLUMN guarantee_flashback_database FOR A3
 
SELECT 
      database_incarnation# as Incar,
      scn,
      name,
      time,
      storage_size,
      guarantee_flashback_database
FROM 
      v$restore_point
ORDER BY 4
/

Datapump Export Script

#
# Title:     datapump_backup.ksh
# Purpose:   Used to take full datapump exports
# Called by: n/a
#
# Notes:     None
#
# Author:    Mark ramsay
# Date:      05 April 2012
#
# Notes:     Requires an oracle directory to be present called data_pump_dir which points to 
#            /u01/app/oracle/admin/${ORACLE_SID}/dpdump
#            Parameter \$1 should be set to the Oracle SID
#            *BE CAREFUL* - The script will remove an dump files from the data_pump_dir
#                           that match the find command.
#

export ORACLE_BASE=/u01/app/oracle
export ORACLE_HOME=$ORACLE_BASE/product/11.2.0/dbhome_1
export PATH=$PATH:$ORACLE_HOME/bin

SDS_date=`date +%d%b%Y`
export ORACLE_SID=$1
export ORAENV_ASK=NO

. oraenv

expdp \"/ as sysdba\" DUMPFILE=${ORACLE_SID}_full_backup_${SDS_date}.dmp DIRECTORY=data_pump_dir Full=y

cd /u01/app/oracle/admin/${ORACLE_SID}/dpdump

find . -name "${ORACLE_SID}_full_backup_*.dmp" -mtime +14 -follow -exec rm {} \;

Using the redo log sizing advisor

The following SQL will give advice on the optimal size of the redo logs, but manual inspection of redo log switch frequency is always the best approach:

SELECT
   (SELECT
      ROUND (AVG (BYTES) / 1024 / 1024, 2)
   FROM
      V$LOG) AS "Redo size (MB)",
   ROUND ( (20 / AVERAGE_PERIOD) * (SELECT AVG (BYTES) FROM V$LOG) / 1024 / 1024, 2) AS "Recommended Size (MB)"
FROM
   (SELECT AVG ( (NEXT_TIME - FIRST_TIME) * 24 * 60) AS   
   AVERAGE_PERIOD
   FROM
   V$ARCHIVED_LOG
   WHERE
   FIRST_TIME > SYSDATE - 3
   AND
   TO_CHAR (FIRST_TIME, 'HH24:MI') BETWEEN '16:00' AND '17:00'); 

How to check if tablespaces are autoextend

select TABLESPACE_NAME, FILE_NAME,AUTOEXTENSIBLE,MAXBYTES from dba_Data_files where TABLESPACE_NAME like 'TS__';

Free space in Auto extensible tablespaces

WITH my_ddf AS
    (
        SELECT file_id, tablespace_name, file_name,
               DECODE (autoextensible,
                       'YES', GREATEST (BYTES, maxbytes),
                       BYTES
                      ) mysize,
              DECODE (autoextensible,
                      'YES', CASE
                         WHEN (maxbytes > BYTES)
                            THEN (maxbytes - BYTES)
                         ELSE 0
                      END,
                      0
                     ) growth
         FROM dba_data_files)
SELECT   my_ddf.tablespace_name,
         ROUND (SUM (my_ddf.mysize) / (1024 * 1024)) totsize,
         ROUND (SUM (growth) / (1024 * 1024)) growth,
         ROUND ((SUM (NVL (freebytes, 0))) / (1024 * 1024)) dfs,
         ROUND ((SUM (NVL (freebytes, 0)) + SUM (growth)) / (1024 * 1024)
               ) totfree,
         ROUND (  (SUM (NVL (freebytes, 0)) + SUM (growth))
                 / SUM (my_ddf.mysize)
                 * 100
               ) perc
    FROM my_ddf, (SELECT   file_id, SUM (BYTES) freebytes
                      FROM dba_free_space
                  GROUP BY file_id) dfs
   WHERE my_ddf.file_id = dfs.file_id(+)
         AND my_ddf.tablespace_name NOT LIKE '%UNDOTB%'
GROUP BY my_ddf.tablespace_name
ORDER BY 6 DESC

To get all information about all tablespaces

http://docs.gz.ro/oracle-display-tablespace-information.html

set lines 230
set echo off
set term off
set trimspool on
set verif off
set feed off
set pagesize 100

column filename format a100
column tablespace format a15
column status format a10 trunc
column autoextend format a10

select
        file_name "Filename",
        tablespace_name "Tablespace",
        round(bytes/1024/1024 ,2) "Current Size (MB)",
        autoextensible "Autoextend",
        round(increment_by*8192/1024/1024 ,2) "Autoextend Size (MB)",
        round(maxbytes/1024/1024 ,2) "Max Size (MB)"
from dba_data_files
order by TABLESPACE_NAME;

Oracle v$block_change_tracking

Enable BLOCK TRACKING

SQL> show parameter db_create_file_dest

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
db_create_file_dest                  string      +DATA_MIRROR01

SQL> ALTER DATABASE ENABLE BLOCK CHANGE TRACKING;
SQL> col filename format a60;
SQL> select filename, status, bytes/1024/1024 from v$block_change_tracking;

FILENAME                                                     STATUS     BYTES/1024/1024
------------------------------------------------------------ ---------- ---------------
+DATA_MIRROR01/ddtest/changetracking/ctf.268.971954405       ENABLED            11.0625

OR create the change tracking file in a location

• ALTER DATABASE ENABLE BLOCK CHANGE TRACKING USING FILE '/mydir/rman_change_track.f' REUSE;

Disable BLOCK TRACKING

SQL> ALTER DATABASE DISABLE BLOCK CHANGE TRACKING;