Free Test Indexing and Hashing – Databas...

Q1: What is the main purpose of indexing in databases?

A. To speed up data retrieval B. To store data sequentially C. To backup data D. To compress data

Q2: Which of the following is a type of single-level index?

A. Primary index B. Multilevel index C. B-tree index D. Bitmap index

Q3: What is a clustered index?

A. An index where the data records are stored in the same order as the index B. An index stored separately from data C. A hash index D. A compressed index

Q4: What type of data structure is commonly used for indexing?

A. B-tree B. Linked list C. Stack D. Queue

Q5: What is hashing?

A. Mapping data to a fixed location using a hash function B. Storing data sequentially C. Creating backups D. Indexing data

Q6: What is a hash collision?

A. When two keys map to the same hash address B. When data is lost C. When index is deleted D. When data is corrupted

Q7: Which method is NOT used to resolve hash collisions?

A. Encryption B. Chaining C. Open addressing D. Rehashing

Q8: What is chaining in hashing?

A. Using linked lists to store multiple elements at the same hash address B. Encrypting data C. Rearranging hash table D. Using indexes

Q9: What does “open addressing” mean in hashing?

A. Finding another empty slot when collision occurs B. Storing data in multiple tables C. Using multiple hash functions D. Backing up data

Q10: What is a secondary index?

A. An index on a non-primary key attribute B. Index on primary key C. Index on clustered data D. Index on hash

Q11: Which of the following is a multilevel index?

A. Index with multiple levels to reduce search time B. Single-level primary index C. Heap file D. Hashed file

Q12: What is the advantage of multilevel indexing?

A. Reduces the size of index searched B. Slows down retrieval C. Increases storage usage D. Causes collisions

Q13: What is a dense index?

A. An index record for every search key value B. Index records for some keys C. Index for primary key only D. Index for hashed values

Q14: What is a sparse index?

A. An index record for only some search key values B. Index record for every key C. Hash index D. Multilevel index

Q15: Which indexing technique is best for range queries?

A. B-tree indexing B. Hashing C. Heap file D. Sequential file

Q16: What does the load factor in hashing represent?

A. Ratio of number of records to number of buckets B. Memory usage C. Index size D. Data redundancy

Q17: Which of these is a disadvantage of hashing?

A. Does not support range queries efficiently B. Slower than sequential search C. Consumes large memory D. Requires frequent backups

Q18: What is the height of a B-tree related to?

A. The number of levels in the tree B. Number of nodes C. Number of records D. Index size

Q19: Which data structure is typically used for multilevel indexing?

A. B-tree B. Heap C. Linked list D. Stack

Q20: What happens when the hash table is full?

A. Rehashing or resizing is performed B. Data is deleted C. Database crashes D. Index is lost

Quiz for Indexing and Hashing