Hashing and Indexing

Question 1

The three major categories of
file organizations are

Answer 1

1) Sequential
2) Indexing
3) Hashing

Question 2

What are sequential index files?

Answer 2

Sequential index files maintain keys in sorted order, allowing for efficient retrieval through sequential access.

Question 3

What is Indexed?

Answer 3

Records are stored sequentially or nonsequentially
and an index is used to keep track of where the records are
stored.

Question 4

What is Hashing?

Answer 4

The address of each record is determined using an algorithm that converts a
primary key value into a record address.

Question 5

Primary Index

Answer 5

A Primary Index is an index structure defined on the ordering key field (the field that is used to physically order records on disk).

Question 6

Clustering Index

Answer 6

When the ordering field is not a key field (i.e not unique) a clustering index is used. They are always sparse.

Question 7

Secondary Index

Answer 7

Secondary Index: An index structure defined on a non-ordering field.

Question 8

Sparse Index

Answer 8

Index records are not created for very search key.

Question 9

What is static hashing?

Answer 9

The hash function always computes the same address for the search key value provided.

Number of data buckets remains constant.

Question 10

Dense Index

Answer 10

An index is created for every record