Indexes

Question 1

What is Indexing?

Answer 1

A data structure technique which allows you to quickly retrieve records from a database file

Question 2

What is a Index?

Answer 2

A small table consisting of two columns

Question 3

What is the first column in an index?

Answer 3

A copy of the primary or candidate key of a table

Question 4

What is the second column in an index?

Answer 4

A set of pointers for holding the address of the disk block where that specific key value stored

Question 5

What are the two main types of indexing methods?

Answer 5

• Primary Indexing

- Secondary Indexing

Question 6

What is a primary index?

Answer 6

An ordered file which is fixed length size with two fields

Question 7

What are the 2 types of primary indexes?

Answer 7

• Dense Index

- Sparse Index

Question 8

What is a dense index?

Answer 8

A record is created for every search key valued in the database

Method records contain search key value and points to the real record on the disk

Question 9

What is the advantage and disadvantage of dense indexing?

Answer 9

+ Helps you to search faster

• Needs more space to store index records

Question 10

What is a sparse index?

Answer 10

A record that appears for only some of the values in the file

Question 11

How does sparse Indexing work?

Answer 11

A range of index columns stores the same data block address, and when data needs to be retrieved, the block address will be fetched