Complete Guide to MySQL BIGINT: Features, Usage & Pitfalls

1. Introduction

2. What is the BIGINT type in MySQL?

Overview of BIGINT type

• Signed (SIGNED): -9,223,372,036,854,775,808 ～ 9,223,372,036,854,775,807
• Unsigned (UNSIGNED): 0 ～ 18,446,744,073,709,551,615

Comparison table of integer types

3. BIGINT Type Usage Examples and Practical Code

User ID and Transaction ID Management

CREATE TABLE users (
    id BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY, -- Unique user ID
    name VARCHAR(255) NOT NULL,                   -- Username
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP -- Creation timestamp
);

Using UNIX Timestamps

CREATE TABLE logs (
    log_id BIGINT PRIMARY KEY,       -- Log ID
    event_time BIGINT NOT NULL       -- Time in UNIX timestamp format
);

Amount and Quantity Management

CREATE (
    sale_id BIGINT AUTO_INCREMENT PRIMARY KEY, -- Sale ID
    amount DECIMAL(10, 2) NOT NULL,            -- Amount (up to two decimal places)
    sale_time TIMESTAMP DEFAULT CURRENT_TIMESTAMP -- Sale time
);

4. Things to Keep in Mind When Using the BIGINT Type

Impact on Storage Usage

Impact on Performance

Compatibility with Other Systems

5. Tips for Effectively Using the BIGINT Type

Criteria for Choosing the Right Data Type

1. Estimate the Maximum Value of the Data

• Consider future scalability and estimate the required data volume and number of digits in advance.
• Example: If 10 million IDs are generated per year and you anticipate operation for more than 20 years, a BIGINT type is required.

1. Consider the Balance with Other Data Types

• For small-scale data, choose INT or SMALLINT to optimize storage space.
• Example: Using TINYINT for small flag management can save space.

1. Plan for Future Data Migration

• To avoid type changes due to data growth, consider scalability from the initial design stage.
• Example: In a user management system where ID growth is expected, setting BIGINT from the start can avoid migration work.

Combining with AUTO_INCREMENT

CREATE TABLE orders (
    order_id BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY, -- Auto-incrementing ID
    customer_id INT UNSIGNED NOT NULL,                  -- Customer ID
    order_date TIMESTAMP DEFAULT CURRENT_TIMESTAMP      -- Order timestamp
);

Index Optimization

1. Adding Indexes

• Set indexes on columns that are frequently queried to improve search speed.

   CREATE INDEX idx_customer_id ON orders(customer_id);

2. Using Composite Indexes

• When searching with multiple conditions, leverage composite indexes.

   CREATE INDEX idx_customer_date ON orders(customer_id, order_date);

3. Applying Partitioning

• If the data volume is massive, consider partitioning for segmented management.

   ALTER TABLE orders PARTITION BY RANGE (YEAR(order_date)) (
       PARTITION p0 VALUES LESS THAN (2023),
       PARTITION p1 VALUES LESS THAN (2024),
       PARTITION p2 VALUES LESS THAN (2025)
   );

6. FAQ (Frequently Asked Questions)

Q1: What is the difference between BIGINT and INT types?

Q2: Should all integer columns be BIGINT?

Q3: How long can BIGINT AUTO_INCREMENT be used?

Q4: What is the difference between signed and unsigned?

Q5: Is it easy to change from INT to BIGINT?

ALTER TABLE users MODIFY id BIGINT;

7. Summary

• The BIGINT type is suitable for large-scale data management and is especially useful for ID management and high-precision numeric processing.
• When choosing a data type, it is important to consider the balance between scalability and performance and design appropriately.
• By leveraging AUTO_INCREMENT and index optimization, you can streamline queries and administrative tasks.