ALLInterview.com :: Home Page KalAajKal.com
 Advertise your Business Here     
Browse  |   Placement Papers  |   Company  |   Code Snippets  |   Certifications  |   Visa Questions
Post Question  |   Post Answer  |   My Panel  |   Search  |   Articles  |   Topics  |   ERRORS new
   Refer this Site  Refer This Site to Your Friends  Site Map  Bookmark this Site  Set it as your HomePage  Contact Us     Login  |  Sign Up                      
tip   To Refer this Site to Your Friends   Click Here
Google
 
Categories  >>  Software  >>  Databases  >>  SQL Server
 
 


 

 
 Oracle interview questions  Oracle Interview Questions
 SQL Server interview questions  SQL Server Interview Questions
 MS Access interview questions  MS Access Interview Questions
 MySQL interview questions  MySQL Interview Questions
 Postgre interview questions  Postgre Interview Questions
 Sybase interview questions  Sybase Interview Questions
 DB Architecture interview questions  DB Architecture Interview Questions
 DB Administration interview questions  DB Administration Interview Questions
 DB Development interview questions  DB Development Interview Questions
 SQL PLSQL interview questions  SQL PLSQL Interview Questions
 Databases AllOther interview questions  Databases AllOther Interview Questions
Question
What is the difference between UNION and UNIONALL?
 Question Submitted By :: Madhukar Subbarayan
I also faced this Question!!     Rank Answer Posted By  
 
  Re: What is the difference between UNION and UNIONALL?
Answer
# 1
UNION statement effectively does a SELECT DISTINCT on the 
results set. If you know that all the records returned are 
unique from your union, use UNION ALL instead, it gives 
faster results.
 
Is This Answer Correct ?    6 Yes 0 No
Suresh
 
  Re: What is the difference between UNION and UNIONALL?
Answer
# 2
union is used to retreive the data with out duplication
union all is used to retreive the data with duplication
 
Is This Answer Correct ?    1 Yes 0 No
Valarmathi
 
 
 

 
 
 
Other SQL Server Interview Questions
 
  Question Asked @ Answers
 
What are statistics, under what circumstances they go out of date, how do you update them? HCL2
i want to join two queries....and i want to run them as one after another that is want output of first query then second , then again output of first query then second and so on...  2
can you any body tell me the how to decrease the logfile  4
how to find number of columns in a table in sql server 2000 and 2005 also Virtusa10
What are the differences between stored procedure and functions in SQL Server 2000? TCS12
how to select 5 to 7 rows from a table, which contains 10 rows? IBM14
Why Do you want to work in this company? HCL3
Hi Can any one tell me the Good institute to learn SQL esp for Data Base Testing or SQL from scratch to the proficiency level in Hyederabad and facult also. Thankyou well in advance  6
Is it possible to have more then one foreign key in a single table? if possible, is this the good way to design the table?  2
How to find out name of all employees who has salary less than 200 Rs.?  7
What's the difference between a primary key and a unique key?  4
Which virtual table does a trigger use?  3
what purpose does OPENXML clause have in sql server stored procedure?  1
what is diffence between replicaion and logshipping?  1
How to restart SQL Server in single user mode? How to start SQL Server in minimal configuration mode?  1
What are mdf,ndf,ldf files and how to see the data in those files? Accenture5
employee table has employee id ----------- empid ---------------- 1 2 3 3 3 4 5 5 5 6 6 6 7 here the values r repeated two times.how to select the repeated values only.i.e 3,5,6 should alone come.  2
what is differece between union and union all  4
Explain the basic concepts of SQL server architecture?  2
Can we rewrite subqueries into simple select statements or with joins? Example? ASD1
 
For more SQL Server Interview Questions Click Here 
 
 
 
 
 
   
Copyright Policy  |  Terms of Service  |  Help  |  Site Map 1  |  Articles  |  Site Map  |   Site Map  |  Contact Us interview questions urls   External Links 
   
Copyright © 2007  ALLInterview.com.  All Rights Reserved.

ALLInterview.com   ::  Forum9.com   ::  KalAajKal.com