Indexes in Database

Question

Hi!!

Can someone tell me what indexes mean in a database?

Answer 1

The index is a data structure that improves the speed of data retrieval operations on a database table at the cost of additional writes and the use of more storage space to maintain the extra copy of data.

Data can be stored only in one order on disk. To support faster access according to different values, a faster search like a binary search for different values is desired, For this purpose, indexes are created on tables. 

These indexes need extra space on disk, but they allow faster search according to different frequently searched values.