What are the purpose for having variable length records, Database Management System

Assignment Help:

What are the purpose for having variable length records? What kinds of separator characters are required for each?

Variable-Length Records - Variable-length records are those records that are of various sizes. A file may holds variable-length records in any of the subsequent situations:

• Records having variable length fields - In this case, the end-of-field symbol along with end-of-record symbol could be used as the separator characters.

• Records having repeating fields - In this case, the number of repetitions of repeating area can be used along with end-of-record symbol as the separator characters.

• Records having optional fields - In this case, the end-of-field symbol along with end-of-record symbol could be used as the separator characters.

• File containing records of various record types - In this case, a special field (or control field) can be prefixed with every record and end-of-record symbol could be used as the separator characters.

In each of the above situations either we can use end-of-record symbol or the length of every record can be prefixed at the starting of the record for the separation of the variable-length records.


Related Discussions:- What are the purpose for having variable length records

Lack of redundancy, Lack of Redundancy We have talked about the problems o...

Lack of Redundancy We have talked about the problems of repetition of information in a database. Such repetition should be stay away as much as possible. Let us state once again t

Design an algorithm to implement operations, Design an algorithm to impleme...

Design an algorithm to implement operations  Each and every operation specified in the functional model could be formulated as an algorithm. The algorithm indicates how operat

In an e-r diagram how attributes are represented, In an E-R diagram how att...

In an E-R diagram how attributes are represented ? In an E-R diagram attributes are represented in a ellipse.

Distributed transaction atomic-consistent-isolated, A distributed transacti...

A distributed transaction consists of subtransactions that execute at different sites and access local DBMSs at those sites. For example, a distributed transaction that transfers m

To eliminate duplicate rows-data manipulation language, To eliminate duplic...

To eliminate duplicate rows (distinct operator)  Example: SELECT DISTINCT DEPTNO FROM EMP;

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

Explain the advantages of database management system, Advantages of Databas...

Advantages of Database management system Let us summarize the advantages. Reduction of Redundancy: This is perhaps the most important advantage of using DBMS. Redundancy i

Which operator is used to compare a value to a list literals, Which operato...

Which operator is used to compare a value to a list of literals values that have been specified? BETWEEN operator is used to compare a value to a list of literals values that h

What way a particular application views data from database, What is the way...

What is the way a particular application views the data from the database that the application uses? Sub schema is the way a particular application views the data from the data

State the objectives of object design, Determine the OBJECTIVES of  object ...

Determine the OBJECTIVES of  object design After passing through this unit, you should be able to: describe and apply concept of generalisation; understand and appl

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