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+23 votes

An index is clustered, if

  1. it is on a set of fields that form a candidate key
  2. it is on a set of fields that include the primary key
  3. the data records of the file are organized in the same order as the data entries of the index
  4. the data records of the file are organized not in the same order as the data entries of the index
asked in Databases by Veteran (407k points) | 3.3k views

2 Answers

+22 votes
Best answer

Answer is C).

Index can be created using any column or combination of column which need not be unique. So, A, B are not the answers.

Indexed column is used to sort rows of table.Whole data record of file is sorted using index so, C is correct option. (Simple video explains this).

answered by (445 points)
edited by
+16 votes

Clustered Index is created on data file whose file recordrds are physically ordered on a non key field which does not have distinct value for each record .

Option A ) Candidate Key

Option B) Primary Key

Option D ) File NOT ordered

Best choice  is Option C

Option C ) Data records are ordered

answered by Boss (21.1k points)
edited by
So, index created on primary key is not clustered?
Index created on primary key will result in single element clusters i.e. no clusters.


I think, answer is correct but explanation isnt.

What you have explained is the definition of clustering index not clustered index.

As per my knowledge clustered index means  the index and the data on which index is have the same order so it doesn't matter whether selected attribute is key or non-key .

( i might be wrong but you can verify once)

what does the term cluster signify?

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