Database Interview Questions
- 0of 0 votes
AnswersWhat's Hbase, Pig, used for? Why do we need Hbase if we can use Hive to query Hadoop?
- Tom Walker June 07, 2015 in United States| Report Duplicate | Flag | PURGE
Microsoft Software Developer Data Mining Data Structures Database Distributed Computing Experience Java Knowledge Based Large Scale Computing - 0of 0 votes
AnswersWhat are different phases of Map reduce operation - I think they were looking for split, combiners, partitioners, sorting phases of whole map reduce stage.
- Tom Walker June 07, 2015 in United States| Report Duplicate | Flag | PURGE
Microsoft Software Developer Data Mining Data Structures Database Distributed Computing Java Large Scale Computing SQL - 0of 0 votes
AnswersMy interview was for big data position for their Search team. They were looking for person with good Hadoop skill set :-
- Tom Walker June 07, 2015 in United States
1. Can you describe Hadoop Architecture? What are various components of it (Primary/Secondary namednodes, data node etc)? Explain working of each.| Report Duplicate | Flag | PURGE
Microsoft Software Developer Data Mining Data Structures Database Distributed Computing Ideas Java - 0of 0 votes
AnswerWhat is a columnar database. why we preferred redshift over mysql for data warehouse.
- kri1311 May 26, 2015 in India| Report Duplicate | Flag | PURGE
Flipkart SDE1 Database - 0of 0 votes
AnswersFrom a web page, each logged in user can click on a plus icon and enter key-value pairs. There is restriction on the entered key and values. Design a schema to store the enter the key-value pairs entered by each user, such that given a key we should be able to retrieve all the username who entered that particular key.
- vinodjayachandran February 03, 2015 in India| Report Duplicate | Flag | PURGE
StartUp Developer Program Engineer Database - 1of 1 vote
AnswersSuppose that there is a database table, and four processes read the table at the same time. But, only one process is allowed to read the same row of the table at the same time. How do you enforce the exclusive-read on a row?
- joeyk December 06, 2014 in United States for Supply Chain| Report Duplicate | Flag | PURGE
Bloomberg LP Software Engineer / Developer Database - 0of 0 votes
AnswersWrite test cases for one command from each category(db related):
- monika.khandelwal1612 September 24, 2014 in India
DDL command
DML command
and also, for
Select command| Report Duplicate | Flag | PURGE
Testing / Quality Assurance Database Testing - 0of 0 votes
AnswersHow do you normalize shopping cart tables?
- User August 26, 2014 in United States| Report Duplicate | Flag | PURGE
Yahoo Software Engineer / Developer Database - 0of 0 votes
AnswersPassword storage rather than storing in DB.
- User August 26, 2014 in United States| Report Duplicate | Flag | PURGE
Yahoo Software Engineer / Developer Database - 0of 0 votes
AnswerHow the tables are stored(different tables structure)
- User August 26, 2014 in United States| Report Duplicate | Flag | PURGE
Yahoo Software Engineer / Developer Database - 0of 2 votes
AnswersDesign a system like friend's functionality in facebook. should have all features of facebook's friends functionality. like for each person , he can have any number of friends , he will get suggestions for new firends , showing common friends if we visits any other profile . algo should be scalable , robust .
- gopi.komanduri August 02, 2014 in United States| Report Duplicate | Flag | PURGE
Computer Scientist Algorithm Android Application / UI Design Arrays Bit Manipulation C# C++ Cache Coding Computer Architecture & Low Level Data Mining Data Structures Database Distributed Computing Dynamic Programming Hash Table Java Large Scale Computing Linked Lists Math & Computation Object Oriented Design Problem Solving Sorting SQL Stacks System Design Trees and Graphs XML - -6of 6 votes
AnswersHow to delete two rows from the table in database ?
- ajaybhardwaj789 May 07, 2014 in India
Note: Delete only first two rows from the Database.
<table style="width:300px" border="2px">
<tr>
<th>USERNAME</th>
<th>LOCATION</th>
</tr>
<tr>
<td>zac</td>
<td>california</td>
</tr>
<tr>
<td>zac</td>
<td>california</td>
</tr>
<tr>
<td>zac</td>
<td>california</td>
</tr>
<tr>
<td>zac</td>
<td>california</td>
</tr>
</table>| Report Duplicate | Flag | PURGE
Google Software Engineer / Developer Database - 0of 0 votes
AnswerWhat approach you will take in migrating your production databases from MySql to Postgre SQL with zero downtime.
- hulk April 26, 2014 in India| Report Duplicate | Flag | PURGE
Collective Software Engineer / Developer Database - 0of 0 votes
AnswersDifference between inner join and left join?
- Xerox March 03, 2014 in United States for AWS| Report Duplicate | Flag | PURGE
Amazon Technical Support Engineer Database - 0of 0 votes
AnswersHow would you design a database to store directory type data structure (e.g. windows folder containing subfolders)?
- A.K. January 15, 2014 in United States for Shared file| Report Duplicate | Flag | PURGE
Citrix System Inc Software Engineer / Developer Database - -4of 4 votes
AnswersWhat should be strategy to minimise the impact on external system which is using our table's data for processing?
- java.interviews.questions October 07, 2013 in India| Report Duplicate | Flag | PURGE
Nomura Applications Developer Database - 0of 0 votes
AnswersHow reverse key index helps in faster data reading and what is use case for this?
- java.interviews.questions September 18, 2013 in India
Complexity of B tree index?| Report Duplicate | Flag | PURGE
Goldman Sachs Applications Developer Database - 0of 2 votes
AnswersDesign a database schema for college elections and how will you make sure at database end that one user can vote for one person standing for one post only.
- coder July 19, 2013 in United States| Report Duplicate | Flag | PURGE
Database - 0of 2 votes
AnswersDesign a database schema for college elections and how will you make sure at database end that one user can vote for one person standing for one post only.
- code July 19, 2013 in United States| Report Duplicate | Flag | PURGE
Database - 4of 4 votes
AnswersTwo tables. Country and City
- sunny smart June 16, 2013 in Netherlands
country --> countryid, country name
city --> countryid, city name
1. how do you get the countries that has no cities?
2. how do you get the countries that has less than 3 cities and also make sure the countries with no cities also show up.| Report Duplicate | Flag | PURGE
Booking.com None None Database SQL - 5of 5 votes
AnswersI have table with columns (Employee, Manager, Salary). Need to calculate aggregate salary for all employees corresponding to top-level managers in one SQL. For example
- breakrulez May 10, 2013 in United States
Input table is :
Emp Manager Salary
A T 10
B A 11
C F 13
D B 5
Result should be :
Top-Lvl Manager Salary(agg)
T 26
F 13
Manager-Employee layering can go multiple levels.| Report Duplicate | Flag | PURGE
Database SQL - 0of 0 votes
AnswersWe have a very large excel file that is produced every day by a batch process. We need to report what records were added and which records were removed compared to the file generated on the previous day. The challenge is that there is no sortable field in the list that we could use (such as a creation date), imagine for the sake of this test that there’s only First Name, Last Name and Email in the excel file, and that the ordering is not consistent from one day to the next. How would you approach the problem?
- zealoftoday May 08, 2013 in United States| Report Duplicate | Flag | PURGE
Database - 0of 0 votes
Answerswhat is Materialized view, is any different from View.
- xuwanglong1988 April 19, 2013 in United States| Report Duplicate | Flag | PURGE
Amazon SDE1 Database - 0of 0 votes
AnswerGiven that a disk page can hold at most 1K bytes, a search key uses 4 bytes, and a pointer uses 4 bytes.
- ael_hsheek@yahoo.com February 15, 2013 in United States
Can we analyze the size of an expendable hashing index to index a table column which is defined using unique constraint. What would be the minimum and maximum size of the expendable hasting index if the bucket address table is fully extended?| Report Duplicate | Flag | PURGE
Zynga Analyst Database - 0of 0 votes
AnswersSuppose a customer buys items for $10 in a shop and the cashier swipe her card at a POS charging $10. Assume that the card has $100 balance before swiping. POS sends the $10 transaction to a machine A in the Amazon cloud. A calls a service to update transaction and card balance, and then sends acknowledgement back to the POS. But the ack got lost in the middle and POS sends another $10 transaction request. How would you make sure that the balance is $90, not $80. And how would you distinguish multiple try with two legitimate $10 transaction back to back.
- zahidbuet106 February 13, 2013 in United States
Hint: You can't use more than one transaction entry in Database and you don't have the rollback provision.| Report Duplicate | Flag | PURGE
Amazon Software Engineer / Developer Database - 0of 0 votes
AnswerDesign a database for storing record of students.
- TechWorld January 25, 2013 in United States for Financial Software Developer| Report Duplicate | Flag | PURGE
Bloomberg LP Intern Database - 0of 0 votes
AnswerDescribe ACID properties in terms of a database transaction
- ravigupt January 19, 2013 in India| Report Duplicate | Flag | PURGE
United HealthGroup Java Developer Database - 0of 0 votes
AnswersDatabase server is in US and web server is in India, how will you handle time zone conversion?
- ravigupt January 19, 2013 in India| Report Duplicate | Flag | PURGE
United HealthGroup Java Developer Database - 0of 0 votes
AnswersHow will you store friend-to-friend relation of facebook in db
- anuj.iiit2007 January 15, 2013 in United States| Report Duplicate | Flag | PURGE
Zynga Database - 0of 0 votes
AnswersI've three tables : Employee,Department,Region as shown below:
- coder87 December 27, 2012 in India
Employee
EmpID, EmpName, Salary
101, 'Karthik', 10000
102, 'Amir', 15000
Department:
DeptID, EmpID, DeptName
3, 101, 'CSE'
4, 100, 'ECE'
Region
RegnID, DeptID, RegnName
10, 3, 'KL'
11, 9, 'DL'
Now i want to print all employee details according to the region (RegnName)they belong to.| Report Duplicate | Flag | PURGE
HCL Software Engineer / Developer Database