Clustering indexes, Database Management System

Clustering Indexes

It may be an excellent idea to keep data of the students in the order of the programme they have registered as most of the data file accesses may need student data of a particular programme only. An index that is formed on an ordered file whose records of a file are physically ordered on a non-key field (that is the field does not have a distinct value for every record) is known as a clustering index.

            1772_Clustering Indexes.png


                                Figure : A clustering Index on Programme of an employee file

                    1031_Clustering Indexes 1.png

Figure: Clustering index with separate blocks for each group of records with the same value for the clustering field

Please note the following points in the tables:

  • Data insertion and deletion is simpler than in the earlier clustering files, even now it is cumbersome.
  • The additional blocks allocated for an index entry are in the kind of linked list blocks.

 • Clustering index is one more example of a non-dense index as it has one entry for each distinct value of the clustering index field and not for all records in the file.

Posted Date: 3/7/2013 6:29:04 AM | Location : United States

Related Discussions:- Clustering indexes, Assignment Help, Ask Question on Clustering indexes, Get Answer, Expert's Help, Clustering indexes Discussions

Write discussion on Clustering indexes
Your posts are moderated
Related Questions
The following variant of the primary copy asynchronous-update replication protocol has been proposed for totally replicated systems. (a)  A transaction executing at site A updat

What are the problems if one were not to normalize?  When do these problems surface?           Ans:  Database normalization, sometimes considered to as  canonical synthesis, is

What are the two types of indices? The two types of indices are:- A)     Dense index B)      Sparse index

Horizontal Fragmentation- Horizontal fragmentation groups together the tuples in a relation that are collectively used by the main transactions. A horizontal fragment is produced b

What is self-transition? If there is a transition which goes back to same state, it is known as "self- transition." With a trigger action exit action would be executed f

recovey techniques based on deferred update and immediate update

Write short note on Events Events consist of inputs, interrupts, decisions and actions performed by any external device or users. Every event always has a sender and receiver.

What is meant by heuristic optimisation?  Discuss the main heuristics that are applied during query optimisation.  Ans:  In heuristic optimization, heuristics are employed to r

I want an iPad app that is a simple 1 page form to complete with text. The Objective is to allow a few dozen people of the same organization (they're all on iPad) to open the app,

a)  Suppose we updated the catalog tables in real time, that is, after every update, insert, or delete SQL statement were executed-rather than only running RUNSTATS once every few