What is index? Explain type of index?


Here I have explained the concept of index. Index is a one important concept in .Net. So you should know the basic idea about index in .Net. I think this will help you while you go to interview.

Learn what is index? And types of index?


Index:
An index is a system used to make finding information easier. Like that we are using index for database table easily retrieve the values. Two types pf index are there
1. Cluster index
2. Non Cluster index

1. Cluster index:
Cluster index having original data. It is physically rearranged data for sorting. You should rearrange the data only one time in table.So only one cluster index can use in your table.

2. Non Cluster index:
Non Cluster index having reference value.here data does not sorted physically.


Comments

Author: sugandha24 Jan 2011 Member Level: Gold   Points : 1

Index is a method used for faster retrieval of
records.different types of indexes are
1.primary key index
2.unique index
3.bitmap index
4.hash index
5.function based index
6.B-tree index(default index created) on table.
7.Virtual index(which do not show entry in DBA_segment).

Author: satyajee srivastava18 Jul 2011 Member Level: Silver   Points : 0

Raj Good Jobs.Try to explain with some examples,for better understanding of the concept.

Author: malini11 Aug 2011 Member Level: Silver   Points : 1

Hi

Indexing is the quick reterival of data from the Database.
where usuall data in the DB is divided in 16 bytes and the searching is happening ,but using index i will search the data in range of 64bytes thats where it is fast.
we have mainly 2 types

1.clustered indexing

2. non clustered indexing

1. 1.clustered indexing
It is physically order data will match with the logically stored for sorting.only one clustered index we can have here.

2. non clustered indexing
In this the physical order of the records will not match the logically stored data it data pages will have 256 indexs

Author: Saravana Perumal18 May 2012 Member Level: Silver   Points : 1

hi raj

I attend one interview. there asked some questions about indexes in sqlserver

how many types of index available in sql and what are they...

can you explain this questions... i just want to clear that...



Thanks & Regards
--------------------
Saravana Perumal.N



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