Interview Questions and Answers for 'Ab' - 364 question(s) found - Order By Rating Q1. Why do we do transformation on the observable itself rather than doing it in the subscriber ? RxJs
Ans. Because that way we just need to do that transformation at one place and not within each subscriber. Single source of truth. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  Angular   Observable  Suscriber Q2. What does pipe does on an observable ? RxJs
Ans. With pipe we specify the operator function to which this observable is passed for transforming the observable. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  Angular   Observable Q3. What is the difference between Subject and Observable ? Angular
This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  subject vs observable Q4. What is the main difference between unique key and primary key ? Database
Ans. Primary key will not accept NULL values whereas Unique key can accept one NULL value.
A table can have only primary key whereas there can be multiple unique key on a table.
A Clustered index automatically created when a primary key is defined whereas Unique key generates the non-clustered index. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  Unique Key  Primary Key Asked in 1 Companies This question was recently asked at 'Oracle financial services'.This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  interface vs abstraction  interfacing vs abstraction  relation between interface and abstraction  How interface provide abstraction Asked in 1 Companies Q6. Difference between XSS and CSRF ? Security
Ans. SRF attack requires an authenticated session, whereas an XSS attack doesn’t.
XSS doesn’t require any user interaction.CSRF is restricted to the actions the victim can perform.
XSS requires a vulnerability to happen, whereas CSRF relies on tricking the user to click a link or access a page.
CSRF can only send an HTTP request but cannot view the response. XSS can send and receive HTTP requests and responses to extract the required data. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  xss attack  csrf attack  security vulnerabilities  security attack  web security Asked in 3 Companies Q7. Can the value of a static variable be changed ? Core Java
Ans. Yes the value of a static variable can be changed. It's the final keyword that restrict the modification of value not static.
Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  static variables Q8. How would you design the database schema for an event? Database
Ans. Broad question, but if the company need velocity, think about use a NO SQL instead of regular SQL databases.
Also prefers materialized views instead of joins to fetch data quickly.
Regarding the database design, there are very good design tools for professional database (to develop proper indexes and good database design) one of the best is QuickDBD Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  database design  database schema Asked in 1 Companies Q9. Why would a cloud customer use resources in multiple regions and zones ? Cloud Computing
Ans. 1. Fault Tolerance
2. Better Access by bringing the application closer to the users. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  Google Cloud Computing (GCP)  Amazon Web Services (AWS)  Availability Zones  Regions and Zones  Infrastructure Q10. differences between drop , delete and truncate Database
This question was recently asked at 'HCL Technologies'.This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Ans. Throwable in java is a class that is the superclass of all exceptions and errors which may occurs in java program.It extends obcect class. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  exception handling   throwable Asked in 1 Companies basic Q12. What is a composite primary key and foreign key ? Database
This question was recently asked at 'jibe development services'.This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Ans. SNMP or Simple Network Management protocol is an application layer protocol for exchanging management information between network devices.
Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 15 Companies Q14. What can be done to protect the application from DDOS attack ? Security
Ans. We can set the max number of requests from a given IP or an IP range
We can set the time out so that a single request cannot hold on to resources for too long.
We can identify patterns ( like too many requests from single IP for single page ) and then block such requests. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  DDOS  security vulnerability Q15. Find the second largest array element without sorting? Design
Ans. We initialize two variables first and second to INT_MIN as,
first = second = INT_MIN
then Start traversing the array,
If the current element in array say arr[i] is greater
than first. Then update first and second as,
second = first
first = arr[i]
If the current element is in between first and second,
then update second to store the value of current variable as
second = arr[i]
then Return the value stored in second. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Q16. How can we increase the speed of SQL queries ? Database
Ans. Using -
1. Prepared Statements
2. Using Indices
3. Using whereby clause only on indexed columns Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Q17. Explain Working of joins in sql. Database
This question was recently asked at 'InfoGain'.This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies This question was recently asked at 'Eurofins IT Solutions'.This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Q19. Write SQL query to join 2 tables ? SQL
Ans. Select * from table1 join Select * from table2 Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  database Asked in 1 Companies Q20. What are different awt constructs ?
This question was recently asked at 'Sabre Corporation'.This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Q21. Differences between MongoDB and mysql. Database
This question was recently asked at 'RiseSmart'.This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Q22. Create DB schema for Employee, Department. Database
This question was recently asked at 'RiseSmart India,RiseSmart'.This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  db schema  database schema  database design Asked in 2 Companies Q23. Sort an Employee Object based on Name or Age Database
Ans. Use Comparable or Comparator interface Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  sql query Asked in 1 Companies Q24. Can we load environment variables into Properties in Java ? How ? Core Java
Ans. Yes
new Properties().putAll(System.getenv()); Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java.util.properties  environment variables Q25. Difference between System.getEnv and System.getProperties ? Core Java
Ans. System.getEnv gets the environment variables where System.getProperties gets Java properties. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  System.getEnv  System.getProperties  environment variables Q26. Does abstract class have public constructor? Core Java
Ans. Yes, an abstract class can have a constructor in Java. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  abstract class  public constructor Asked in 1 Companies Q27. What is the minimum number of tables required to perform a SQL join? Database
Ans. 1 , We can do self join
Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  sql join Asked in 1 Companies Ans. No Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  aws dynamodb  aws nosql database  amazon cloud nosql database Q29. Difference between composite , primary and unique key ? Database
This question was recently asked at 'Thomson reuters'.This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Q30. create an SQL query across multiple tables involving outer joins Database
Ans. Select * from table1 t1Left outer join table2 t2 on t1.tid = t2.id Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  sql query  database  outer joins Asked in 2 Companies