NIIT SQL/PLSQL Interview Questions

Explain about Oracle Architecture?
What happens when query is executed?Explain.
What is library cache,Data Dictionary?
What is Result Cache?What is deterministic?
What is collection. Have u declared constructor in collections? Which collection have u used?
What is Multiset operator?
How to find lock on table? 
If application is working slow. what are the issues? (Data volume is not changed,No network issues).
What is explain plan. How do u read explain plan. What informtion does it show?
What is statistics.
If we create a new table say emp, no statistics is generated, no records are inserted than
whether explain plan will be generated?
What are anyalytical function? LAG,LEAD?
What is overloading? Can procedure be overloaded?
What is pragma Autonomous Transaction?
What is Trigger.Can we commit in trigger? Compound Trigger?
Can we commit in compound triggers?
Can function be called from Trigger?
Information about syntax check in library cache is obtained from?
Information about symantic check in library cache is obtained from?
What is Soft parse,Hard parse?
A table has record with value 20. updating the value as 30, what information would be in undo segment and what in redo logs.
What is the minimum no of redo logs required?
Whether Archiver process is necessary?

Genpact PLSQL/SQL Interview Questions

Tell about your experience and your skills.
SQL Loader how it is used.
when External tables are used.
Difference between external tables and SQL loader.
Can i have the same name for a procudure and function? Explain the reason.
What is bitmap index.
is view updatable.
How to make view non updatable.
What are the conditions in which view is not  updatable.
What is materializabe view, In  which scenario will you use materializable view.
What is instead of trigger.
How do you generated 1 to 9 numbers.
I have a table with values in a column from 1 to 9. I want to show all the values from 1 to 9 in a single one column of a row.
There is a name called 'ALEXANDER'. How do u find the count of A in that name.
From the above question find the count of a with out using regular expression.
What is the difference between RANK and DENSE_RANK.
I have  a histroy table , where it will have the history of the rates daily. I want to keep the data for 90 days and from 91 onwards no need to keep in the table. How will you desing a table.
What is the cost in SQL Explain Plan.
What other things you look while checking the SQL plan.
If the plan Cost is low , does that mean the sql query is faster. Explain .

Fidelity - Performance Tuning Interview Questions

What is AWR, ADDM, ASH
What is the difference between AWR, ADDM
Tell a scenaio when u have used AWR
What are the different wait events
What db sequential file read, db scattered read events, and its difference.
What is a cursor.
what are its attributes
what is type , rowtype
what is bulk collect
how do u identify the limit set to bulk collect
What is the difference between btree and bitmap index.
There is an sql statement that ran fine in  the morining, but in the evening its taking long time. How do u identify the issue and tune the statement.
How do u find the difference in SQL plans of the same statement if there is a change in the SQL plan.

Fidelity Interview Questions

Screening test on call:
What is AWR and ADDM
What is ASH
What is Explain Plan
What are events in oracle
What Bulk collect
What is cursor
What is refcursor


First Round - Face to Face :
What is Collection . Types of Collections in PLSQL? 
Write the syntax of Associative Array.
When should we use Associative array , nested tables?
What is Ref cursor. Can it be passed as parameter in SP and functions? 
Type of ref cursors?
What is explicit Cursor. How to find that data in the cursor is not available.
Query to fetch all the columns of the of highest paying departments.
What is TKPROF ? How to enable the SQL Trace.  Write the statement enable tracing.
On setting the SQL Trace parameter, where does this parameters value is stored in database.
What information are there in TKPROF.
What is normalization. Explain 1st NF,2nd NF, 3rd NF with examples.