To minimize disk I/O, which of these should be chosen?

CHAR, VARCHAR

Solution (By Examveda Team)

This question is about choosing the right data type in MySQL to reduce how much your database needs to read and write data from your computer's hard drive (disk I/O). This is important because less disk I/O means your database runs faster!
Let's break down the options:
* CHAR: This data type stores fixed-length strings. It means that no matter how long your actual text is, CHAR will always reserve the same amount of space.
* VARCHAR: This data type stores variable-length strings. It means that VARCHAR only uses as much space as your actual text needs.
So, which one minimizes disk I/O?
Option B: VARCHAR is the better choice because it uses less space than CHAR. Remember, less space means less data to read and write, leading to less disk I/O and a faster database.
Why not CHAR?
CHAR, although simple, can waste space. If you have a short string like "cat" stored in a CHAR(10) field, you'll still reserve 10 characters worth of space, even though you only used 3. This wasted space leads to more disk I/O.
In Summary:
For storing strings of varying lengths, VARCHAR is generally the best option to minimize disk I/O and improve database performance.