Useful Unix command for Oracle DBA

Unix command for Oracle DBAOracle DBA need to operate on Unix/Linux/Solaris/AIX Operating system. He has to locate various file, process, kill session ,clear directories, schedule cron and various other activities. Here in this article I am trying to give some Useful Unix command for Oracle DBA  to help them in day-to-day activities.These same commands are applicable for Linux also. Hope you like it


How to kill all similar processes with single command (in this case java)


ps -ef | grep java |grep -v grep | awk ‘{print $2}’ |xargs -i kill -9 {}

Locating Files under a particular directory

find . -print |grep -i xyz.sql

Cleanup any unwanted trace files more than seven days old

find . *.trc -mtime +7 -exec rm {} ;

To remove a specific column of output from a UNIX command – for example to determine the UNIX process Ids for all Oracle processes on server (second column)

ps -ef |grep -i oracle |awk ‘{ print $2 }’

Changing the standard prompt for Oracle Users
Edit the .profile for the oracle user


Display top 10 CPU consumers using the ps command

/usr/ucb/ps auxgw | head -11

Show number of active Oracle dedicated connection users for a particular ORACLE_SID

ps -ef | grep $ORACLE_SID|grep -v grep|grep -v ora_|wc -l

Display the number of CPU’s in Solaris

psrinfo -v | grep “Status of processor”|wc -l

How to schedule a Job in Unix

Use cronjob
crontab -l ( list current jobs in cron)
crontab -e ( edit current jobs in cron )
_1_ _2_ _3_ _4_ _5_ $Job_Name
1 – Minutes (0-59)
2 – Hours ( 0-24)
3 – day of month ( 1- 31 )
4 – Month ( 1-12)
5 – A day of week ( 0- 6 ) 0 -> sunday 1-> monday
e.g. 0 0 1 * 5 Means run job at Midnight on 1st of month & every friday

Crontab examples

To submit a task every Tuesday (day 2) at 2:45PM

45 14 2 * * /opt/oracle/scripts/ > /dev/null 2>&1

To submit a task to run every 15 minutes on weekdays (days 1-5)

15,30,45 * 1-5 * * /opt/oracle/scripts/ > /dev/null 2>&1

To submit a task to run every hour at 15 minutes past the hour on weekends (days 6 and 0)

15 * 0,6 * * opt/oracle/scripts/ > /dev/null 2>&1


Show all links

find . -type l -exec ls -ld {} ;

show all directiries

find . -type d -exec ls -ld {} ;

How to find the release in Linux

cat /etc/*-release

To print the top 10 largest “files and directories”:

$ du -a . | sort -nr | head

To print the top 10 largest files names (not directories) in a particular directory and its sub directories

$ find . -printf ‘%s %p\n’|sort -nr|head

To restrict the search to the present directory use “-maxdepth 1” with find.

$ find . -maxdepth 1 -printf ‘%s %p\n’|sort -nr|head

How to check if a Port is listening for any Service

netstat -an | grep <port no>

How to find the symbolic links that point to the old path in your oracle_home and appl_top.

ls -al `find . -type l` | grep $OLD_PATH


To find CPU in Solaris

uname -X

To find files modified in the last  n mins:

find . -mmin -n

 To find files modified before n mins:

find . -mmin +n

How To Check Environment Variables for a Running Process


In Linux,

strings –a /proc/<pid_of_the_process>/environ

In Solaris,

pargs -e <pid_of_the_process>


pargs or ps eww <pid_of_the_process>

Display n lines after match

grep -A <n> “string” FILENAME

Display N lines before match


grep -B <n> “string” FILENAME

Searching in all files recursively using grep -r

grep -r “tom” *


Eliminate empty and commented lines

sed -e ‘s/#.*//;/^$/d’ filename.txt

Eliminate Comments Using sed

sed -e ‘s/#.*//’ filename.txt

Display One File Per Line Using ls -1

ls -1

Display File Size in Human Readable Format Using ls -lh

$ ls -lh

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