Views-data control, Database Management System

Assignment Help:

Views

A view is like a window by which data from tables can be changed or viewed. The table on which a view is based is known as Base table. The view is stored as a SELECT statement in the data dictionary. When the user needs to retrieve data, using view. Then the following steps are defined.

1)  View definition is finding from data dictionary table. For example, the view definitions in oracle are to be finding from table name USER-VIEWS.

2)  Checks access privileges for the view base table.

3)  Changes the view query into an equivalent operation on the underlying base table

 

 


Related Discussions:- Views-data control

Which data manipulation command combines the records, Which data manipulati...

Which data manipulation command combines the records from one or more tables ? JOIN data manipulation command combines the records from one or more tables.

Define deferred update technique of recovery, Discuss deferred update techn...

Discuss deferred update technique of recovery.  What are the advantages?  Ans:  The deferred update methods do not physically update the database on disk till after a transact

Explain the term- data flows, Explain the term- Data Flows Data Flows:...

Explain the term- Data Flows Data Flows: A data flow connects output of an object or process to input of another process or object. It represents an in-between data value wit

When are two schedules said to be view equivalent, When are two schedules s...

When are two schedules said to be view equivalent?     Ans: Two schedules that is denoted as S and S' are said to be view equivalent if the subsequent three conditions are met

Two types of blocks in the fixed -length representation, What are the two t...

What are the two types of blocks in the fixed -length representation? Define them. Anchor block: Have the first record of a chain. Overflow block: Have the records other tha

Queries, Find the names of all Albums that have more than 30 tracks. Result...

Find the names of all Albums that have more than 30 tracks. Result: (name: varchar(255))

Give the forms of triggers, Give the forms of triggers? The triggering ...

Give the forms of triggers? The triggering event can be insert or delete. For updated the trigger can state columns. The referencing old row as clause The referencing

Give an expression within sql for queries, Consider the following relations...

Consider the following relations:  S (S#, SNAME, STATUS, CITY)  SP (S#, P#, QTY)  P (P#, PNAME, COLOR, WEIGHT, CITY) Give an expression within SQL for each of queries b

What is dml, What is DML (Data Manipulation Language)? This language th...

What is DML (Data Manipulation Language)? This language that enable user to access or manipulate data as organised by appropriate data model. Procedural DML or Low level: DM

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