Sunday, May 24, 2020

Database Management Systems (DBMS) Question Bank 01

DBMS question bank - why database administrators do not create index on every attribute of every relational table?


Why database administrators typically do NOT create an index on every single attribute of every single relation?


  • Indexes are separate tables. They consume extra space - In database, the indexes that we create in a table are stored as separate relations. They consume extra space. For example, if an index is created on an attribute X of relation R, then X will consists of at least two columns, one for index attribute and the other for pointer.
  • Indexes slows-down the data queries that try to INSERT, DELETE or UPDATE data in the database - The records (keys) in indexes are stored in sorted order. This property helps in speeding up the look-up process. So, whenever we perform INSERT, DELETE, or UPDATE operation on the base table, the records in index has to be adjusted. This slows-down the process.


Featured Content

Multiple choice questions in Natural Language Processing Home

MCQ in Natural Language Processing, Quiz questions with answers in NLP, Top interview questions in NLP with answers Multiple Choice Que...

All time most popular contents

data recovery