Explain retrieval in qbe, Database Management System

Assignment Help:

Explain retrieval in QBE?

Retrieval in QBE : A "GUI" for expressing queries.

  1. Based on the Domain Relational Calculus (DRC)
  2. Actually invented before GUIs.
  3. Very convenient for simple queries.
  4. Awkward for complex queries.
  5. QBE and IBM trademark.

But has influenced many projects Especially PC Databases: Paradox, Access, etc.


Related Discussions:- Explain retrieval in qbe

What is an entity relationship model, What is an entity relationship model?...

What is an entity relationship model?  The  entity  relationship  model  is  a  collection  of  basic  objects  known as entities  and  relationship  between  those objects. An

Relational operations, Let us now talk about the relational operations: ...

Let us now talk about the relational operations: SELECT The select operation is used to select few specific record from the database based on different criteria, This is a un

What is the use of raid, What is the use of RAID? A variety of disk-org...

What is the use of RAID? A variety of disk-organization methods, collectively called redundant arrays of independent disks are used to better the performance and reliability.

What is an object design, What is an object design? Object design is a ...

What is an object design? Object design is a very interactive method, which decides the relationship among objects, classifies operations on classes, determines overall system

Data aggregation, Q.   Explain  data aggregatio n and discuss differen...

Q.   Explain  data aggregatio n and discuss different design constraints. Sol. Aggregation   One limitation of the E-R model is that it cannot express relationships amon

xml, basic structure of xm

basic structure of xml

Database backup, Discuss the importance and characteristics of database bac...

Discuss the importance and characteristics of database backup and recovery procedures, then describe the actions that must be detailed in backup and recovery plan

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.

Mention constraints to create command ddl, Mention the type of constraints ...

Mention the type of constraints we can specify in the CREATE command of DDL. The type of constraints that can be specified are as follows:- PRIMARY KEY, NOT NULL, UNIQUE, FOR

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