Query optimization

Question

What is Query Optimization?can any one explain with a realtime scenario please...

Please dont share the links..like theory Parts.Every one know the theory but we are expecting practical knowledge from this Site...

Thanks in advance

Rajesh Singh · Answer

1) Hi Please refer some more example. 1. Instead of NOT In Operator we have to use Exists Operator. 2. For filtering we need to use where clause at the same time should not use Having clause until unless We required to use aggregate functions. 3. Always avoid the use of SUBSTRING function in the query. 4. While there is case to use IN or BETWEEN clauses in the query it is always advisable to use BETWEEN for better result.

Rajesh Singh · Answer

Hi Please refer my blog for more info. http://dotnetmagic.blogspot.in/2015/12/sql-server-performance-tuning-tips.html Let me know if u need any other help.

jayachandra b · Answer

Thank u soomuch...........

Rajesh Singh · Answer

Hi Query optimization is process of improving performance of Application which is using sql server. I will give one simple example. Let suppose you are accessing data from table 'Student' Select * from Student Mention name of columns which you want to access from db not *(star). select name roll from Student You can get more info about query optimization in google. I hope this will help.

jayachandra b · Answer

can u please explain with one more example.....