How does indexing improve query performance?

Answer Posted / praveen

By creating index on single or multiple columns, query
takes index access path instead of full table scan. Full
table scan is costilier operation where it has to visit all
rows in the table whereas index operation just accesses the
index sub table with required hash value and joins with the
basetable using rowid. This improves response time and
performance of the query.

Is This Answer Correct ?    28 Yes 3 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

What can be achieved by using the teradata rdbms?

829


What are the different design perspectives used in teradata?

769


Explain Teradata performance tuning and optimization?

942


What is spool space? Why do you get spool space errors?

727


What is meant by a Clique?

825


Name the five phases that come under MultiLoad Utility.

786


Syntax for case when statement?

848


Is multi insert ansi standard?

1972


Difference between stored procedure and macro?

938


Difference between inner join and outer join?

807


Explain the most common data types used in teradata?

799


What does Amp contain and what are all the operations that it performs?

794


how can we analyze the locks ?

1894


What is smp and mpp platforms?

739


What are the functions of a Parser?

826