UNIT-IV 2

What is the main focus of module 29 in database management systems?

• Indexing and hashing

• Query optimization

• Machine learning

• Data visualization

What is the most powerful data structure introduced in the last module?

• Linked list

• Hash table

• B+ tree

• Binary search tree

What is the basic logical concept of a bucket in hash file organization?

• A unit of storage containing one or more records

• A single record

• A search key value

• A disk block

What is the purpose of a hash function in hash file organization?

• To locate records directly from their search key value

• To encrypt data

• To sort records alphabetically

• To compress data

What is the worst possible hash function according to the text?

• One that maps each key to a unique bucket

• One that uses a B+ tree structure

• One that maps all key values to the same bucket

• One that generates random bucket addresses

What is the main advantage of dynamic hashing over static hashing?

• Requires less memory

• Eliminates the need for hash functions

• Allows the number of buckets to change dynamically

• Provides faster access time

What is the primary disadvantage of static hashing?

• Requires periodic reorganization

• Has a high memory overhead

• Does not support index structures

• Has slow access time

Which database system supports hash index but does not recommend it?

• PostgreSQL

• MySQL

• Oracle

• SQL Server

What is the main advantage of bitmap indices?

• Provides real-time data processing

• Requires less disk space

• Supports complex data types

• Efficient for querying on multiple keys

What operation can be easily computed using bitmap indices?

• Division and multiplication

• Exponentiation and logarithm

• Intersection and union

• Addition and subtraction