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

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

Consistency, what do you mean by consistency in rdbms?

what do you mean by consistency in rdbms?

Abap/4 program, It is not possible to make an ABAP/4 program, which having ...

It is not possible to make an ABAP/4 program, which having only Subroutines. False. We can make ABAP/4 program, which having only Subroutines.

DW Job Scheduling, Define a job scheduling strategy that will meet business...

Define a job scheduling strategy that will meet business requirement of reporting availability by 6am CST for the following cubes? Show the job scheduling dependencies in a pictori

Define deadlock detection, Define Deadlock detection If a system does ...

Define Deadlock detection If a system does not employ a few protocols that make sure deadlock freedom, after that a detection and recovery scheme should be used. An algorithm

Illustrate the term- abstracting out common behaviour, Illustrate the term-...

Illustrate the term- Abstracting Out Common Behaviour Inheritance is not every time recognised during analysis phase of development, thus it is necessary to re-evaluate object

Explain the timestamps for read operations, Timestamps For Read operations:...

Timestamps For Read operations: If TS (T) If TS (T) >= W-timestamp (Q), then the transaction T is trying to read a value of data item Q which has been written and committed

Explain the integrity constraints, Explain the integrity constraints: Not N...

Explain the integrity constraints: Not Null,  Unique, Primary Key with an example each. Is the combination 'Not Null, Primary Key' a valid combination. Justify. Not Null - Shou

Modular growth, Modular growth: In distributed environments, it is simple t...

Modular growth: In distributed environments, it is simple to expand. Latest sites can be added to the network without affecting the operations of other sites, as they are somewhat

Sql, example of embedded SQL query

example of embedded SQL query

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