mysql优化

碎片清理

-- 查看碎片占比
SELECT 
    table_name, 
    ROUND((DATA_FREE / (DATA_LENGTH + INDEX_LENGTH + DATA_FREE)) * 100, 2) AS 'Fragmentation_Percentage'
FROM 
    information_schema.TABLES
WHERE 
    TABLE_SCHEMA = '库名'
ORDER BY 
    Fragmentation_Percentage DESC;
-- 清理碎片
ALTER TABLE 表名 engine=InnoDB;