INSTALLATION INTERVIEW QUESTIONS
Explain the steps of installing oracle 10g on a linux machine
Refer to the installation guide in class notes
What is the purpose of adding oinstall and dba groups?
oinstall – to provide the user to install any oracle software
dba – allows to administer the database
Is it compulsory that we need to give group names as oinstall and dba? Or can we give any other name?
We can give any name, but those are oracle standards
What are kernel parameters and why to set them?
They will define the memory allocation from physical memory to Oracle database
What is the difference in installing 10g and 11g on linux?
11g allows to set kernel parameter later whereas in 10g we need to do it before
What is Oracle inventory?
It is a location which provides the oracle product information which are installed on a particular host
Why to run orainstRoot.sh and root.sh scripts at the end of installation?
orainstRoot.sh will change the permissions for oraInventory and root.sh will create oratab file
When I am trying SQLPLUS, its throwing command not found error. How you will handle it?
We need to set oracle bin directory in PATH environment variable
Where you will set environment variables in linux? Why to set them?
We need to set in .bash_profile file. Setting them will help in easy access to commands
How you will set environment variables in windows?
We can set in advanced tab in mycomputer properties
When trying to connect to the database, I am getting “net service name is incorrectly specified” error. What is the reason?
ORACLE_SID is not set
How to check how many databases are up and running at OS level?
ps –ef | grep smon. Even though this is the generic command that is used, this is not the perfect answer as it will give output even if instance is started. So the correct answer would be ps –ef | grep oracle. In the output, we need to see for processes which says LOCAL=NO which means someone connected to the database from remote machine
How to check the version and bit version of oracle software?
SQL> select * from v$version;
How to check how many databases are existing on the server?
Using oratab file. But this may not give perfect answer if manually created databases are not updated
How many databases can we create on a single server?
Unlimited until cpu and memory configuration are supported
How many databases are there in your environment and categorize them?
Tell any value between 70 to 100. Out of that say 35 are prod and rest are dev and test
What is the highest size of the databases you are maintaining?
Tell any value between 400 to 700 GB
How many servers are there in your project? Which platforms you are comfortable to work in?
Tell any value between 30 to 50. Platforms are all unix and windows flavours
Can we change the block size after database creation?
No, we cannot
What are the 3 important steps after database created manually?
Executing catalog.sql script
Updating oratab file
Executing catproc.sql script
How to see background process at DB level?
SQL> select program from v$session;
How to start the database if pfile is not in default location?
SQL> startup pfile=’location of pfile’
I am creating a database manually and while executing script, I am getting “ORACLE INSTANCE TERMINATED, DISCONNECTION FORCED” error. What went wrong and how you will troubleshoot?
This is due to UNDO tablespace name mismatch between create database script and pfile. Once fixed, problem will be resolved
What is the difference between ORACLE_BASE and ORACLE_HOME?
ORACLE_BASE is the location where we can install oracle software and ORACLE_HOME is the database home location
How to automate database startup during linux bootupbshut and dbstart scripts
25.What is your strategy to delete old traces?
We will delete them every 3 months except alert log. We will take backup of alertlog and will trim the file
26.How to check RAM size at OS level?
We can user free or top command
27.How to check the size of a single directory?
- du –sk*
It is used to know the IO and memory statistics
28.While starting the database, I am getting “END OF FILE ON COMMUNICATION CHANNEL” error. You are the only user connected to the database. What could be the reason for this?
- If a particular mount point is full, in that case we will get that error
29.What are different types of SCN available?
- We have TOP, START, STOP, BLOCK SCN etc
- 30.How many types of checkpoints are there?
- We have nearly 10 checkpoints which helps in making data permanent in different stages of transaction
- 31.What is the use of oratab file?
- To identify how many databases existing on a server
32.How do you check if oracle installed on a server?
- By checking orainventory location
- 33.If I have 5 databases on a server, how to find which version they are?
- By checking oratab file