How to use data archiving in MySQL to optimize storage space?

How to use data archiving in MySQL to optimize storage space?

Introduction:
As the amount of data continues to grow, the storage requirements of the database are also increasing. In order to optimize storage space, we can move infrequently accessed data to archive tables through data archiving, and use MySQL's partitioning function to further improve query performance. This article will introduce how to use data archiving in MySQL to optimize storage space, and provide relevant code examples for readers' reference.

1. What is data archiving?
Data archiving refers to moving infrequently accessed data to independent archive tables, thereby reducing the amount of data in the main table. Archive tables do not participate in regular query operations, but they still retain the ability to query and analyze historical data. This can free up valuable storage space without affecting normal business operations.

2. Data archiving steps and sample code:
The following is a step and sample code for using data archiving to optimize storage space:

Step 1: Create the main table and archive table

--Create main table
CREATE TABLE main_table (
id INT(11) NOT NULL AUTO_INCREMENT,
col1 VARCHAR(255) NOT NULL,
col2 INT(11) NOT NULL,
created_at DATETIME NOT NULL,
PRIMARY KEY (id ),
KEY idx_col1 (col1)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

-- Create archive table
CREATE TABLE archive_table (
id INT(11) NOT NULL AUTO_INCREMENT,
col1 VARCHAR(255) NOT NULL,
col2 INT(11) NOT NULL,
created_at DATETIME NOT NULL,
PRIMARY KEY (id),
KEY idx_col1 (col1)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

Step 2: Create a partition table

--Create a partition table of the main table
ALTER TABLE main_table PARTITION BY RANGE (YEAR(created_at))
(
PARTITION p2020 VALUES LESS THAN (2021),
PARTITION p2021 VALUES LESS THAN MAXVALUE
) ;

Step 3: Create a trigger

--Create a trigger and insert data into the archive table
DELIMITER //
CREATE TRIGGER archive_trigger AFTER DELETE ON main_table
FOR EACH ROW
BEGIN
INSERT INTO archive_table VALUES (OLD.id, OLD.col1, OLD.col2, OLD.created_at) ;
END//

DELIMITER ;

Step 4: Test data insertion and query effects

--Insert test data into the main table
INSERT INTO main_table (col1, col2, created_at) VALUES ('data1', 1, '2020-01-01');
INSERT INTO main_table (col1, col2, created_at) VALUES ('data2', 2, '2021-01-01');

-- Query main table data
SELECT * FROM main_table;

- - Query archive table data
SELECT * FROM archive_table;

Step 5: Archive data regularly

--Archive old data into the archive table regularly
DELIMITER //
CREATE EVENT archive_event
ON SCHEDULE EVERY 1 WEEK STARTS NOW()
DO
BEGIN
INSERT INTO archive_table SELECT * FROM main_table WHERE created_at < DATE_SUB(NOW(), INTERVAL 1 MONTH);
DELETE FROM main_table WHERE created_at < DATE_SUB(NOW(), INTERVAL 1 MONTH);
END //

DELIMITER ;

Through the above steps and code examples, we have implemented the data archiving operation. The data in the main table is partitioned according to the creation time, and the deleted data is inserted into the archive table through triggers. At the same time, we also archive expired data from the main table to the archive table by regularly archiving data.

3. Conclusion
By using data archiving technology, we can reduce the amount of data in the main table and optimize storage space. At the same time, by using MySQL's partitioning function, we can also improve query performance. We hope that the introduction and sample code of this article can help readers better understand and apply data archiving technology.

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