MySQL超大数据量查询与删除优化的详细方案

-- 创建时间分区表
CREATE TABLE logs (
    id BIGINT AUTO_INCREMENT,
    event TEXT,
    log_time DATETIME
) PARTITION BY RANGE (YEAR(log_time)) (
    PARTITION p2020 VALUES LESS THAN (2021),
    PARTITION p2021 VALUES LESS THAN (2022)
);

-- 直接删除整个分区（秒级完成）
ALTER TABLE logs DROP PARTITION p2020;

-- 每次删除10万条，循环执行
WHILE (EXISTS (SELECT 1 FROM orders WHERE create_time < '2025-01-01' LIMIT 1)) DO
    START TRANSACTION;
    DELETE FROM orders 
    WHERE create_time < '2025-01-01' 
    ORDER BY id 
    LIMIT 100000;
    COMMIT;
    DO SLEEP(0.5); -- 避免锁竞争
END WHILE;

-- 创建临时表存储待删主键
CREATE TEMPORARY TABLE tmp_ids 
ENGINE=Memory
SELECT id FROM large_table WHERE condition LIMIT 100000;

-- 通过主键关联删除
DELETE FROM large_table
WHERE id IN (SELECT id FROM tmp_ids);

-- 将历史数据归档到独立表
CREATE TABLE archive_table LIKE original_table;
INSERT INTO archive_table 
SELECT * FROM original_table 
WHERE create_time < '2025-01-01';

-- 清空原表后重建
TRUNCATE TABLE original_table;

-- 创建内存索引加速查询
ALTER TABLE huge_table ADD INDEX idx_temp (create_time) USING BTREE;
DELETE FROM huge_table WHERE create_time < '2025-01-01';

-- 查看当前删除进度
SHOW PROCESSLIST;
-- 监控锁等待
SELECT * FROM information_schema.INNODB_TRX;
-- 观察redo log写入量
SHOW ENGINE INNODB STATUS;

-- 创建恢复点
SAVEPOINT delete_savepoint;
-- 错误时回滚
ROLLBACK TO delete_savepoint;

-- 通过binlog实现延迟删除
SET @binlog_pos = (SELECT position FROM mysql.binlog WHERE event_type = 'delete');
-- 误删后回滚
mysqlbinlog --stop-position=@binlog_pos binlog.000001 | mysql -u root

[mysqld]
innodb_buffer_pool_size = 128G  # 占物理内存80%
innodb_log_file_size = 4G       # 减少日志刷盘频率
max_allowed_packet = 256M       # 避免大事务报错