Crontab job to run every 5 minutes, for example

Just a small note, if you ever need to run a job in crontab every 5 minutes, let’s say, this is the way to do it:  (as opposed to writing 00,05,10,15….)

*/5 * * * * /u01/app/oracle/bin/ora_rm_arc MYDB 24 > /dev/null 2>&1

How to hint query based on a view?

Sometimes we need to add a hint on a query, which is based on a view.
For examples:

SQL>select name from all_employees_v where id > 101;

Since employees_v is a complex view, can we still add a hint to manipulate the optimizer, without modifying the view?

The answer is yes and is very nice detailed in the link below:

http://alexzeng.wordpress.com/2013/12/29/how-to-add-hint-for-sql-using-oracle-view/

Thank you Alex for sharing :-)

setsid Unix command to the rescue!

Assuming you have a main script, which is running a few other scripts in nohup in the background, and at the end, you want to run "tail -f" for the log file in a loop, until done.
If you press Ctrl-C, the main script will die, together with all the other scripts running in nohup, not exactly the desired result.

For example:

Main.sh:

nohup ./script1  > ${NOHUP_FILE1} 2>&1 &
nohup ./script2  > ${NOHUP_FILE2} 2>&1 &

RUN_IND=0
while [ $RUN_IND -eq 0 ]  ; do
ps -ef |grep Main |grep -v grep  > /dev/null
RUN_IND=$?
tail  -5   ${NOHUP_FILE1}
sleep 5
done

The solution will be to replace nohup by setsid, as below:

Main.sh:

setsid./script1  > ${NOHUP_FILE1} 2>&1 &
setsid./script2  > ${NOHUP_FILE2} 2>&1 &

RUN_IND=0
while [ $RUN_IND -eq 0 ]  ; do
ps -ef |grep Main |grep -v grep  > /dev/null
RUN_IND=$?
tail  -5   ${NOHUP_FILE1}
sleep 5
done

How to avoid printing sqlplus query output on the screen?

Sometimes, we have a shell script and inside we run a SQL query and we just want to spool the result in a file, without printing the output on the screen.
SET TERMOUT OFF will do the job, but only if it is inside a SQL script.

So this will work:

echo "set pages 0 feedback off  heads off echo off TERMOUT off" >> ${sql_v}
echo "spool Tmp/db.lst" >> ${sql_v}
echo "select distinct  db_name  from my_table order by  1;" >> ${sql_v}
echo "spool off " >> ${sql_v}
echo "exit; " >> ${sql_v}

sqlplus -s $MY_DB_CONNECT  @${sql_v}

But this will NOT work:

sqlplus -s $MY_DB_CONNECT << ENDofSql1
set pages 0 feedback off  heads off echo off TERM OFF
select distinct  db_name  from my_table order by  ENV_CODE;
exit
ENDofSql1

I thought of mentioning this, since it can be frustrating at times...

Annoying oracle error during software installation

It may happen that you install first oracle server/client in a specific directory and then you'd like to do a brand new installation, but you are getting the error below, even after you've completely removed the OH:

[INS-32025] The chosen installation conflicts with software already installed in the given Oracle home.

The solution is to tamper with the configuration file:

oraInventory/ContentsXML/inventory.xml

First create a backup of the above file and then remove the lines related to the previous installation.

Arithmetic inside Linux ksh script

Sometimes, you write a shell script and the need arises for a little arithemtic inside. There are a few ways to do this, below is the simplest way, in my opinion; this is a very simple example, to calculate the percentage done by a specific job:

#!/bin/ksh

total=27800
done=`grep 9k4dgqum1pkdh MYDB_ora_7519.trc |wc -l`


s=`echo "${done}*100/${total}" | bc`

echo "Completed : ${s}%"

How to choose the sequence file number to use for restore/duplicate RMAN command?

Connect to the RMAN respositor:

 rman target /

 List the available backups; choose the latest sequence log number and add one when you run the restore/duplicate DB command.
 In the example below, I've used 15628+1


 RMAN>list backup;

BS Key  Size       Device Type Elapsed Time Completion Time
------- ---------- ----------- ------------ --------------------
282     302.50K    DISK        00:00:00     03-DEC-2013 13:53:14
        BP Key: 284   Status: AVAILABLE  Compressed: YES  Tag: ENV_52_DB_BKP
        Piece Name: /TESTDB11/ora_data02/RMAN_backup/TESTDB11/TESTDB11_UAT52_TBS_DB_BKUP_13:52:58-12-03-2013_1_287.rman

  List of Archived Logs in backup set 282
  Thrd Seq     Low SCN    Low Time             Next SCN   Next Time
  ---- ------- ---------- -------------------- ---------- ---------
  1    15625   10218583388335 03-DEC-2013 13:35:02 10218583388844 03-DEC-2013 13:45:02
  1    15626   10218583388844 03-DEC-2013 13:45:02 10218583389173 03-DEC-2013 13:53:13
  1    15627   10218583389173 03-DEC-2013 13:53:13 10218583389183 03-DEC-2013 13:53:13

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ --------------------
283     Full    4.47G      DISK        00:14:43     03-DEC-2013 14:08:01
        BP Key: 285   Status: AVAILABLE  Compressed: YES  Tag: ENV_52_DB_BKP
        Piece Name: /TESTDB11/ora_data02/RMAN_backup/TESTDB11/TESTDB11_UAT52_TBS_DB_BKUP_13:52:58-12-03-2013_1_288.rman
  List of Datafiles in backup set 283
  File LV Type Ckp SCN    Ckp Time             Name
  ---- -- ---- ---------- -------------------- ----
  1       Full 10218583389193 03-DEC-2013 13:53:18 /TESTDB11/ora_data00/system_TESTDB11_01.dbf
  2       Full 10218583389193 03-DEC-2013 13:53:18 /TESTDB11/ora_data00/sysaux_TESTDB11_01.dbf
  3       Full 10218583389193 03-DEC-2013 13:53:18 /TESTDB11/ora_data00/undotbs_TESTDB11_01.dbf
  4       Full 10218583389193 03-DEC-2013 13:53:18 /TESTDB11/ora_data00/tools_TESTDB11_01.dbf
  9       Full 10218583389193 03-DEC-2013 13:53:18 /TESTDB11/ora_data00/bmluapp52_TESTDB11_01.dbf
  28      Full 10218583389193 03-DEC-2013 13:53:18 /TESTDB11/ora_data00/bmluref52_TESTDB11_01.dbf
  47      Full 10218583389193 03-DEC-2013 13:53:18 /TESTDB11/ora_data00/bmluopr52_TESTDB11_01.dbf
  67      Full 10218583389193 03-DEC-2013 13:53:18 /TESTDB11/ora_data00/bmluref52f_TESTDB11_01.dbf
  70      Full 10218583389193 03-DEC-2013 13:53:18 /TESTDB11/ora_data00/bmluapp52f_TESTDB11_01.dbf

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ --------------------
284     Full    1.33M      DISK        00:00:01     03-DEC-2013 14:08:04
        BP Key: 286   Status: AVAILABLE  Compressed: YES  Tag: ENV_52_DB_BKP
        Piece Name: /TESTDB11/ora_data02/RMAN_backup/TESTDB11/TESTDB11_UAT52_TBS_DB_BKUP_13:52:58-12-03-2013_1_289.rman
  Control File Included: Ckp SCN: 10218583390120   Ckp time: 03-DEC-2013 14:08:03

BS Key  Size       Device Type Elapsed Time Completion Time
------- ---------- ----------- ------------ --------------------
285     1.38M      DISK        00:00:00     03-DEC-2013 14:08:05
        BP Key: 287   Status: AVAILABLE  Compressed: YES  Tag: ENV_52_DB_BKP
        Piece Name: /TESTDB11/ora_data02/RMAN_backup/TESTDB11/TESTDB11_UAT52_TBS_DB_BKUP_13:52:58-12-03-2013_1_290.rman

  List of Archived Logs in backup set 285
  Thrd Seq     Low SCN    Low Time             Next SCN   Next Time
  ---- ------- ---------- -------------------- ---------- ---------
  1    15628   10218583389183 03-DEC-2013 13:53:13 10218583390129 03-DEC-2013 14:08:05

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ --------------------
286     Full    1.33M      DISK        00:00:01     03-DEC-2013 14:08:08
        BP Key: 288   Status: AVAILABLE  Compressed: YES  Tag: TAG20131203T140807
        Piece Name: /TESTDB11/ora_data02/RMAN_backup/TESTDB11/ctl/CTLBKP_TESTDB11_13:52:58-12-03-2013.CTL
  Control File Included: Ckp SCN: 10218583390148   Ckp time: 03-DEC-2013 14:08:07

 The duplicate command looks like:

 RUN {
SET NEWNAME FOR DATAFILE 1  TO '/testdb11/ora_data02/RMAN_backup/auxiliary_dest/dbf/system01.dbf';
SET NEWNAME FOR DATAFILE 2  TO '/testdb11/ora_data02/RMAN_backup/auxiliary_dest/dbf/sysaux.dbf';
SET NEWNAME FOR DATAFILE 3  TO '/testdb11/ora_data02/RMAN_backup/auxiliary_dest/dbf/undotbs01.dbf';
SET NEWNAME FOR DATAFILE 4  TO '/testdb11/ora_data02/RMAN_backup/auxiliary_dest/dbf/tools01.dbf';
SET NEWNAME FOR DATAFILE 9  TO '/testdb11/ora_data02/RMAN_backup/auxiliary_dest/dbf/bmluapp52.dbf';
set until sequence 15629 thread 1;
DUPLICATE TARGET DATABASE TO AUXU
TABLESPACE test52,TOOLS
  LOGFILE
    GROUP 1 ('/testdb11/ora_data02/RMAN_backup/auxiliary_dest/redo/redo01a.log',
             '/testdb11/ora_data02/RMAN_backup/auxiliary_dest/redo/redo01b.log') SIZE 200M reuse,
    GROUP 2 ('/testdb11/ora_data02/RMAN_backup/auxiliary_dest/redo/redo02a.log',
             '/testdb11/ora_data02/RMAN_backup/auxiliary_dest/redo/redo02b.log') SIZE 200M reuse;

}