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

Determine the three views of data, Determine the Three Views of Data We...

Determine the Three Views of Data We know that the similar thing, if viewed from dissimilar angles produces difference sights. Similarly, the database that we have formed alrea

Determine the object-oriented design process, An object-oriented design pro...

An object-oriented design process  1. Define the context and modes 2. Designs the system architecture 3. Identifies the principal system objects 4. Identifies concurrency in

Principles of good e-governance, Question: (a) e-Government implementa...

Question: (a) e-Government implementations normally evolve through a multi-stage process. Describe, using appropriate examples, the stages involved in an e-Government implemen

Example of grant create session to mca12, Example -GRANT CREATE SESSION TO ...

Example -GRANT CREATE SESSION TO MCA12; (This command gives system level permission on creating a session - not portable) GRANT SELECT ON EMP TO MCA12; (Object level permi

Differance between join and outer join, Differentiate between join and oute...

Differentiate between join and outer join? Outer joins return all rows from at least one of the tables or views mentioned within the FROM clause, as long as those rows get toge

Define page, Define page. The database is partitioned into some number ...

Define page. The database is partitioned into some number of fixed-length blocks, which are referred to as pages.

Ddl compiler-database management system, DDL Compiler The DDL compile...

DDL Compiler The DDL compiler changes the data definition statements (such as CREATE TABLE .... in SQL) into a set of tables having metadata tables. These tables have infor

Need point of sale software for pizza restaurant, Project Description: N...

Project Description: Need Point of Sale software for pizza restaurant. Delivery and take out service, client's database, inventory control, order history, last order, order from

find a non-redundant cover and canonical cove, Given the following set of ...

Given the following set of functional dependencies {cf→ bg, g → d, cdg → f, b → de, d → c} defined on R(b,c,d,e,f,g) a. Is cf→ e implied by the FDs? b. Is dg a superkey?

HYRISE, how to implement hyrise in C plus plus

how to implement hyrise in C plus plus

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