Int(20) vs. BigInt(20) in MySQL: What's the Real Difference?

Understanding the Difference Between BigInt(20) and Int(20) in MySQL

Differentiating between data types is crucial for optimized database design in MySQL. Int(20) and BigInt(20) are commonly used for storing numeric data, but their precise distinctions can sometimes be confusing.

Type Definitions and Storage Capacity

• INT: A signed 4-byte integer, capable of storing values ranging from -(2³¹-1) to 2³¹-1.
• BIGINT: A signed 8-byte integer, boasting a significantly larger range of possible values: -(2⁶³-1) to 2⁶³-1.

Display Width Deception

The numerical suffix (20) in both INT(20) and BigInt(20) may lead to misunderstandings. It does not indicate any storage size limit, but rather serves as a display width hint. This hint suggests the preferred width of the number for visual representation purposes only.

Zero-Filling Effect

However, the display width hint does have an impact on the ZEROFILL option. With this option enabled, zero padding will be applied to the value to match the specified width.

Choosing the Right Type

To select between Int(20) and BigInt(20) effectively, consider the following guidelines:

• For values within the range of -(2³¹-1) to 2³¹-1, Int(20) is sufficient.
• For values exceeding this range, BigInt(20) is necessary due to its larger storage capacity.

By understanding these distinctions, you can make informed decisions when choosing data types for your MySQL database, ensuring optimal storage and retrieval efficiency.

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