Creation of indexes, Database Management System

Assignment Help:

Creation of Indexes

Automatically: When a primary key or Unique constraint is show in a table definition then a unique index is formed automatically.

Manually: User can form non-unique indexes on columns to speed up access time to rows.

Example: The following commands produce index on employee name and employee name + department number respectively.

CREATE INDEX EMP_ENAME_IDX ON EMP (ENAME);

CREATE INDEX EMP_MULTI_IDX ON EMP (ENAME, DEPTNO);

Finding facts about created indexes: The data dictionary have the name of index, table name and column names. For instance, in Oracle a user-indexes and user-ind-columns see contains the details about user formed indexes.

Remove an index from the data dictionary:

DROP INDEX EMP_ENAME_IDX;

Indexes cannot be modified.


Related Discussions:- Creation of indexes

Business process model, Consider a research paper submission process. The p...

Consider a research paper submission process. The process starts when an author submits a draft research paper (the paper may have up to 3 authors) to the chair of the organizing c

ER diagram, construct an er diagram for a hospital with a set of patients a...

construct an er diagram for a hospital with a set of patients and a set of medical doctors. associate with each patient a log of various test and examination conducted.convert er d

Differentiate sub-class and super-class, Differentiate sub-class and super-...

Differentiate sub-class and super-class? The specialization of a class is known as subclasses.eg: employee is a subclass of person and teller is a subclass of employee. Convers

Give concurrent sub states diagram for the classroom, Give Concurrent sub s...

Give Concurrent sub states diagram for the classroom and exam held. In Figure, simultaneous substrates have been taken. After passing Minor 1 test you could give Minor 2 test. T

What is a database, What is a database? Database - Basically in simpl...

What is a database? Database - Basically in simple terms A database is a collection of inter related data and/or information stored so which it is available to several users

Data base model, why are older data base model are being replaced by new da...

why are older data base model are being replaced by new data model

Whta is the advantage of the database management approach, Whta is the adva...

Whta is the advantage of the database management approach? The advantage of the database management approach is data is integrated and can be accessed by multiple programs.

Design and building a distributed information system, prototype of a distri...

prototype of a distributed information system for a national car part retail outlet chain.

Entity set or entity type, A collection of a same kind of entities is known...

A collection of a same kind of entities is known as an Entity Set or entity type. Example: For the COLLEGE database defines earlier objects of concern are Students, Faculty,

Architectural standard, Architectural standard: Designation : Archit...

Architectural standard: Designation : Architect , Consultant Job Profile : As a part of Oracle Fusion Middleware at Satyam, I am involved with Presales, Delivery, A

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd