File organisation in dbms, Database Management System

File Organisation In Dbms

Introduction

Databases are used to store information. Usually, the principal operations we have to perform on database are those relating to:

  • Retrieving data
  • Creation of data
  • Modifying
  • Removing some information which we are sure is no longer useful or valid.

We have seen that in terms of the logical operations to be done on the data, relational tables give a good mechanism for the entire over tasks. Thus the storage of a database in a computer memory (on the hard disk, of course), is mainly concerned with the following issues:

  • They require storing a set of tables, where every table can be stored as an independent file.
  • The attributes in a table are closely related and, thus, often accessed together. Thus it makes sense to store the dissimilar attribute values in every record contiguously. In fact, is it essential that the attributes must be stored in the similar series, for each record of a table?
  • It seems logical to store all the records of a table contiguously. Though, since there is no prescribed order in which records must be stored in a table, we may choose the series in which we store the dissimilar records of a table.

We shall see that the point (iii) between these observations is quite needful. Databases are used to store information in the form of files of records and are typically stored on magnetic disks. This section focuses on the file Organisation in DBMS, the access methods available and the system parameters related with them. File Organisation is the way the files are in order on the disk and access method is how the data can be retrieved based on the file Organisation.

Posted Date: 3/7/2013 2:34:24 AM | Location : United States







Related Discussions:- File organisation in dbms, Assignment Help, Ask Question on File organisation in dbms, Get Answer, Expert's Help, File organisation in dbms Discussions

Write discussion on File organisation in dbms
Your posts are moderated
Related Questions
Define the terms   i) DDL   ii) DML   DDL: Data base schema is specified by a set of definitions expressed by a special   language known as a data def

Performance of Various Concurrency Control Mechanisms

What are called multilevel indices? Indices with two or more levels are known as multilevel indices.

What are the two types of serializability? The two types of serializability is a)      Conflict serializability b)      View serializability

Which is the properties of entities? Attributes is the properties of entities.

Explain the θ-join and equijoin Refer tables Car and Boat which list models of cars and boats and their relevant prices. Assume a customer wants to buy a car and a boat, but sh

Describe the algorithm for updating indices for a single level index when a record is    (i) Inserted  (ii)  deleted What will be the modification if there are multilevel in

Improved performance: As the data is located near the site of its demand, and given the inherent parallelism because of multiple copies, speed of database access may be good for di

Define and differentiate between ordered indexing and hashing. Ans: Ordered indexing: To gain fast random access to records in a file, we can make of an index structure. Every

Define entity integrity and referential integrity.  How does SQL allow specification of  these? Ans: Entity Integrity Rule- If the attribute A of relation R is a prime attribut