1. 查询语法结构 ~~~ SELECT [ALL | DISTINCT | DISTINCTROW ] [HIGH_PRIORITY] [STRAIGHT_JOIN] [SQL_SMALL_RESULT] [SQL_BIG_RESULT] [SQL_BUFFER_RESULT] [SQL_CACHE | SQL_NO_CACHE] [SQL_CALC_FOUND_ROWS] select_expr [, select_expr ...] [FROM table_references [PARTITION partition_list] [WHERE where_condition] [GROUP BY {col_name | expr | position} [ASC | DESC], ... [WITH ROLLUP]] [HAVING where_condition] [ORDER BY {col_name | expr | position} [ASC | DESC], ...] [LIMIT {[offset,] row_count | row_count OFFSET offset}] [PROCEDURE procedure_name(argument_list)] [INTO OUTFILE 'file_name' [CHARACTER SET charset_name] export_options | INTO DUMPFILE 'file_name' | INTO var_name [, var_name]] [FOR UPDATE | LOCK IN SHARE MODE]] ~~~ 1. 优化更需要优化的Query； 2. 定位优化对象的性能瓶颈； 3. 明确的优化目标； 4. 从Explain入手； 5. 多使用profile 6. 永远用小结果集驱动大的结果集； 7. 尽可能在索引中完成排序； 8. 只取出自己需要的Columns； 9. 仅仅使用最有效的过滤条件； 10.尽可能避免复杂的Join和子查询； 合理设计并利用索引