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

In tuple relational calculus p1- p2 is equivalent to, In tuple relational ...

In tuple relational calculus P1 → P2 is equivalent to ? A In tuple relational calculus P1→  P2 is equivalent to ¬P1 V P2. (The logical implication expression A  B, meaning

Define shared locks, Define Shared locks? Ans: Shared lock: Throughout ...

Define Shared locks? Ans: Shared lock: Throughout concurrent execution of transactions, earlier than a transaction can access a data item, it has to obtain a lock on it. Now he

Describe in brief about the sequence diagrams, Describe in brief about the ...

Describe in brief about the Sequence Diagrams Sequence diagrams are interaction diagrams which emphasize time ordering of messages. In UML, it is shown as a table which shows

Differentiate between various levels of data abstraction, Differentiate bet...

Differentiate between various levels of data abstraction? Data Abstraction - Abstraction is the procedure to hide the irrelevant things from the users and represent the rele

Transaction, .#question. Discuss the problem which may arise during concurr...

.#question. Discuss the problem which may arise during concurrency control and recovery in distributed database which are not encountered in controlized database environment.

ERD DIAGRAM, Law Associates is a large legal practice based in Sydney. You...

Law Associates is a large legal practice based in Sydney. You have been asked to design a data model for the practice based upon the following specification: The practice employs

Define the concept of aggregation, Define the concept of aggregation.  Give...

Define the concept of aggregation.  Give two examples where this concept is useful. Ans: Aggregation transforms a relationship among the objects into a higher-level object. A

What is derived and stored attribute, What is Derived and stored Attribute?...

What is Derived and stored Attribute? Derived and Stored Attribute - In a few cases, two or more attribute values are associated, for example, Age and BirthDate attributes of a

Need database normalization and database analysis, Developer is required to...

Developer is required to do a task including: - Database Normalization - Database Analysis - ERM Diagram Details can be provided and then you can change your bid accord

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