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Unix sysadmin interview questions

Unix sysadmin interview questions

Q: How would you make the following SQL statement run faster? SELECT * FROM TABLEA WHERE COL1=A AND COL2=B’;
A: Make sure that COL1 and COL2 have indexes.
Find out which condition will return less values and use that as the first conditonal.

Q: What is Data Mining
A: Data Minig is the process of sifting through extremeley large amounts of Data to find trends or relevent information.

Q: Name the Seven layers in the OSI Model.
A: Appication, Presentation, Session, Transport, Network, Data Link, Phyiscal Read more…

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Linux admin interview questions

Linux admin interview questions

How do you list the files in an UNIX directory while also showing hidden files? ls -ltra

How do you execute a UNIX command in the background? Use the &”.

What UNIX command will control the default file permissions when files are created? umask

Explain the read, write, and execute permissions on a UNIX directory. Read allows you to see and list the directory contents. Write allows you to create, edit and delete files and subdirectories in the directory. Execute gives you the permissions to run programs or shells from the directory. Read more…

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Unix/Linux administration interview questions

Unix/Linux administration interview questions

What is LILO?

LILO stands for Linux boot loader. It will load the MBR, master boot record, into the memory, and tell the system which partition and hard drive to boot from.

What is the main advantage of creating links to a file instead of copies of the file?

A: The main advantage is not really that it saves disk space (though it does that too) but, rather, that a change of permissions on the file is applied to all the link access points. The link will show permissions of lrwxrwxrwx but that is for the link itself and not the access to the file to which the link points. Thus if you want to change the permissions for a command, such as su, you only have to do it on the original. With copies you have to find all of the copies and change permission on each of the copies.

Write a command to find all of the files which have been accessed within the last 30 days.

find / -type f -atime -30 > December.files

This command will find all the files under root, which is /, with file type is file. -atime -30? will give all the files accessed less than 30 days ago. And the output will put into a file call December.files. Read more…

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Interview questions for Linux admin

Interview questions for Linux admin

Advantages/disadvantages of script vs compiled program.

Name a replacement for PHP/Perl/MySQL/Linux/Apache and show main differences.

Why have you choosen such a combination of products?

Differences between two last MySQL versions. Which one would you choose and when/why?

Main differences between Apache 1.x and 2.x. Why is 2.x not so popular? Which one would you choose and when/why?

Which Linux distros do you have experience with? Read more…

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Unix/Linux programming interview questions

Unix/Linux programming interview questions

Question 1: What is the major advantage of a hash table? (Asked by Silicon Magic Corp. people)

Answer: The major advantage of a hash table is its speed. Because the hash function is to take a range of key values and transform them into index values in such a way that the key values are distributed randomly across all the indices of a hash table.

Question 2: What are the techniques that you use to handle the collisions in hash tables?(Asked by Silicon Magic Corp. people)

Answer: We can use two major techniques to handle the collisions. They are open addressing and separate chaining. In open addressing, data items that hash to a full array cell are placed in another cell in the array. In separate chaining, each array element consist of a linked list. All data items hashing to a given array index are inserted in that list. Read more…

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