What is data defination language, Database Management System

Assignment Help:

What is DDL? Make a list of commands with short description used in DDL

Ans: Data Definition Language that is abbreviated as DDL is a computer language for defining data structures. The phrase was first introduced in relation to the Codasyl database model in which the schema of the database was written in a Data Definition Language explaining the records, fields, and "sets" making up the user Data Model.

  List of DDL commands:

  (a) To define a table/ relation

  CREATE TABLE ------

  (b) To eliminate table/relation definition

DROP TABLE ----

  (iii) To alter the definition of an existing table

  ALTER TABLE-------


Related Discussions:- What is data defination language

Difference between functions along with or without grouping, Explain the di...

Explain the difference between using functions along with and without grouping attributes in relational algebra. Give examples. Ans: Group functions are used to group data of

Database recovery and security, Database Recovery And Security Introdu...

Database Recovery And Security Introduction In this part we will introduce two main issues relating to database management systems. A computer system suffers from dissi

What is natural language interfaces, What is Natural Language Interfaces? ...

What is Natural Language Interfaces? Natural Language Interfaces - These interfaces accept requests written within English or a few other language and attempt to "understand" t

Objectives of database manangement system, OBJECTIVES After going thro...

OBJECTIVES After going through this unit you should be capable to: Explain the File Based system and its limitations; Explain the structure of DBMS; Explain the

Explain domain calculus, Explain Domain calculus Domain calculus is one...

Explain Domain calculus Domain calculus is one of the types of the relational calculus. The formal specification of the domain calculus was planned after the development of the

Rules of data normalisation, Rules Of Data Normalisation  Let us now su...

Rules Of Data Normalisation  Let us now summarise Normalisation with the help of various clean rules. The following are the necessary rules for the Normalisation process: 1.

Write short notes on relational constraints, Write short notes on relationa...

Write short notes on relational constraints? Relational Constraints are: 1. NOT NULL 2. Unique 3. Primary key 4. Foreign key 5. Table check

Give an example of object representation, Give an example of Object Represe...

Give an example of Object Representation  For illustration, consider the implementation of a social security number within an employee object that is shown in Figure. The soci

What is thread splitting, What is Thread splitting A thread of cont...

What is Thread splitting A thread of control is a path by which a set of state diagrams on that a single object is active at a time. Objects are shared between threads

Explain the shadow paging recovery technique, Explain the shadow paging rec...

Explain the shadow paging recovery technique.  Ans: Shadow paging is a method used to acquire atomic and durable transactions, and provides the capability to manipulate pages i

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