ISRO CSE 2007 | Question: 50

Question

A view of database that appears to an application program is known as

• A. Schema
• B. Subschema
• C. Virtual table
• D. None of these

Comments

The schema is the physical arrangement of the data as it appears in the DBMS.

 

The sub-schema is the logical view of the data as it appears to the application program.

 

Answer is sub-schema

Answer 1

The external level is the user’s view of the database and closest to the users.This level describes that part of the database that Fundamentals of Database Management .System is relevant to the user. Most of the users of database are not concerned with
all the information contained in the database. Instead, they need only a part of  the  database  relevant  to  them. An external schema describes each external view. The external schema consists of the definition of the logical records
and the relationships in the external view.

A subschema expresses the external view.External schema are called also called as sub schemas .

So option B is correct.

Comments

what is a Virtual table?

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A virtual table is the common term for a database View.

A View is a saved SQL query that is presented to the user as a standard database table. It doesn't store any data itself; instead, it dynamically generates its content from one or more underlying tables whenever it's accessed.

Think of a View as a saved shortcut or a custom filter for your data. For example, you might have a huge Employees table with lots of sensitive information, but you want your HR assistant to only see the names and phone numbers of employees in the 'Sales' department.

 

Answer 2

A subschema is a subset of the schema and inherits the same property that a schema has. Subschema refers to an application programmer's (user's) view of the data item types and record types, which he or she uses. It gives the users a window through which he/she can view only that part of the database, which is of interest to him. Therefore, different application programs can have a different view of data.

Answer 3

subschema

Comments

reference ,pg no-23

http://iete-elan.ac.in/SolQP/soln/DC10_sol.pdf

Answer 4

Answer is b) Subschema 

A sub-schema is best described as the way that the data in a DBMS appears when viewed by an application or a user. The most important criteria for a sub-schema is that it appears logically, and as part of a decipherable system.