Drop Down MenusCSS Drop Down MenuPure CSS Dropdown Menu

UNIX Interview Questions for Oracle DBAs

1) What’s the difference between soft link and hard link?

A symbolic (soft) linked file and the targeted file can be located on the same or different file system while for a hard link they must be located on the same file system, because they share same inode number and an inode table is unique to a file system, both must be on the same file system.

2) How you will read a file from shell script?
while read line
 echo $line
done < file_name

3) 3. What’s the use of umask?
Will decide the default permissions for files.

4) What is crontab and what are the arguments?
The entries have the following elements:
field             allowed values
-----             --------------
minute            0-59
hour                0-23
day of month   1-31
month             1-12
day of week     0-7 (both 0 and 7 are Sunday)
user                 Valid OS user
command         Valid command or script

? ? ? ? ? command
|  | |  | |_________day of the week (0-6, 0=Sunday)
|  | |  |___________month (1-12)
|  | |_____________day of the month (1-31)
|  |_______________hour (0-23)
|_________________minute (0-59)

5) How to find operating system (OS) version?
uname –a

6)  How to find out the run level of the user?
uname –r

7) How to delete 7 days old trace files?
find ./trace –name *.trc –mtime +7 –exec rm {} \;

8) What is top command?
top is a operating system command, it will display top processes which are taking high cpu and memory.

9) 8. How to get 10th line of a file (by using grep)?


Popular posts from this blog

Script to find sessions that are blocking other sessions in PostgreSQL

How to find the server is whether standby (slave) or primary(master) in Postgresql replication ?

How to Get Table Size, Database Size, Indexes Size, schema Size, Tablespace Size, column Size in PostgreSQL Database

PostgreSQL pgBadger

How to Return a Result Set from a PostgreSQL Stored Procedure