MySQL 8.0 使用 ALGORITHM=INSTANT算法，即时添加或删除列，有64次数限制

当达到行版本64次限制时，操作将被拒绝，

并给出错误信息，建议使用 COPY 或 INPLACE 算法重建表。

4092 (HY000): Maximum row versions reached for table test/t1.

No more columns can be added or dropped instantly. Please use COPY/INPLACE.

自 MySQL 9.1.0 起，次数上升为 255。

复现

-- 创建测试表

CREATE TABLE test_instant_limit (
    id INT PRIMARY KEY
);

-- 使用存储过程来执行65次ALTER TABLE操作

DELIMITER //
CREATE PROCEDURE test_instant_limit_procedure()
BEGIN
    DECLARE i INT DEFAULT 1;
    DECLARE alter_result VARCHAR(255);
    
    -- 循环64次，使用INSTANT算法添加列
    WHILE i <= 64 DO
        SET @sql = CONCAT('ALTER TABLE test_instant_limit ADD COLUMN col_', i, ' INT, ALGORITHM=INSTANT');
        PREPARE stmt FROM @sql;
        EXECUTE stmt;
        DEALLOCATE PREPARE stmt;
        
        SELECT CONCAT('成功添加列 col_', i, ' 使用INSTANT算法') INTO alter_result;
        SELECT alter_result;
        
        SET i = i + 1;
    END WHILE;
    
    -- 尝试第65次INSTANT更改
    BEGIN
        DECLARE CONTINUE HANDLER FOR SQLEXCEPTION
        BEGIN
            GET DIAGNOSTICS CONDITION 1 @sqlstate = RETURNED_SQLSTATE, @errno = MYSQL_ERRNO, @text = MESSAGE_TEXT;
            SET alter_result = CONCAT('错误：', @errno, ' (', @sqlstate, '): ', @text);
        END;
        
        SET @sql = 'ALTER TABLE test_instant_limit ADD COLUMN col_65 INT, ALGORITHM=INSTANT';
        PREPARE stmt FROM @sql;
        EXECUTE stmt;
        DEALLOCATE PREPARE stmt;
        
        IF alter_result IS NULL THEN
            SET alter_result = '成功添加列 col_65 使用INSTANT算法（超出预期）';
        END IF;
        
        SELECT alter_result;
    END;
END //
DELIMITER ;

-- 执行存储过程

CALL test_instant_limit_procedure();

参考手册：

https://dev.mysql.com/doc/refman/8.4/en/innodb-online-ddl-operations.html