admin 发表于 2012-3-28 02:48:38

mysql执行时间的语句。。。

直接用命令行工具,显示如下。

mysql> select * from a;
+------+------+
| id | name |
+------+------+
| 1 | A |
| 2 | B |
| 3 | C |
| 4 | D |
| 5 | E |
| 6 | A |
| 7 | B |
| 8 | C |
| 9 | D |
| 10 | E |
+------+------+
10 rows in set (0.03 sec)

mysql>
----------------------------------------

set profiling=1
select * from tb
show profiles


---------------------------------------
那就自己写个脚本

select now() as beginetime;
select ........
select now() as endTime

使用MYSQL行命令批处理这些语句,并发结果重定向到文件
---------------------------------------
Mysql的SQL语句执行时间
查看 MySQL 語法 詳細執行時間 與 CPU/記憶體使用量: MySQL Query Profiler

MySQL 的 SQL 語法調整主要都是使用 EXPLAIN , 但是這個並沒辦法知道詳細的 Ram(Memory)/CPU 等使用量.

於 MySQL 5.0.37 以上開始支援 MySQL Query Profiler, 可以查詢到此 SQL 會執行多少時間, 並看出 CPU/Memory 使用量, 執行過程中 System lock, Table lock 花多少時間等等.

MySQL Query Profile 詳細介紹可見: Using the New MySQL Query Profiler (2007.04.05 發表)

效能分析主要分下述三種(轉載自上篇):

  * Bottleneck analysis - focuses on answering the questions: What is my database server waiting on; what is a user connection waiting on; what is a piece of SQL code waiting on?
  * Workload analysis - examines the server and who is logged on to determine the resource usage and activity of each.
  * Ratio-based analysis - utilizes a number of rule-of-thumb ratios to gauge performance of a database, user connection, or piece of code.

MySQL Query Profile 使用方法
啟動

  * mysql> set profiling=1; # 此命令於 MySQL 會於 information_schema 的 database 建立一個 PROFILING 的 table 來紀錄.

SQL profiles show

  * mysql> show profiles; # 從啟動之後所有語法及使用時間, 含錯誤語法都會紀錄.
  * ex: (root@localhost) > show profiles; # 注意 Query_ID, 下面執行時間統計等, 都是依 Query_ID 在紀錄

  +----------+------------+---------------------------+
  | Query_ID | Duration | Query |
  +----------+------------+---------------------------+
  | 1 | 0.00090400 | show profile for query 1 |
  | 2 | 0.00008700 | select * from users |
  | 3 | 0.00183800 | show tables |
  | 4 | 0.00027600 | mysql> show profiles |
  +----------+------------+---------------------------+
  

查詢所有花費時間加總

  * mysql> select sum(duration) from information_schema.profiling where query_id=1; # Query ID = 1

  +---------------+
  | sum(duration) |
  +---------------+
  | 0.000447 |
  +---------------+
  

查詢各執行階段花費多少時間

  * mysql> show profile for query 1; # Query ID = 1

  +--------------------+------------+
  | Status | Duration |
  +--------------------+------------+
  | (initialization) | 0.00006300 |
  | Opening tables | 0.00001400 |
  | System lock | 0.00000600 |
  | Table lock | 0.00001000 |
  | init | 0.00002200 |
  | optimizing | 0.00001100 |
  | statistics | 0.00009300 |
  | preparing | 0.00001700 |
  | executing | 0.00000700 |
  | Sending data | 0.00016800 |
  | end | 0.00000700 |
  | query end | 0.00000500 |
  | freeing items | 0.00001200 |
  | closing tables | 0.00000800 |
  | logging slow query | 0.00000400 |
  +--------------------+------------+
  

查詢各執行階段花費的各種資源列表

  * mysql> show profile cpu for query 1; # Query ID = 1

  +--------------------------------+----------+----------+------------+
  | Status | Duration | CPU_user | CPU_system |
  +--------------------------------+----------+----------+------------+
  | (initialization) | 0.000007 | 0 | 0 |
  | checking query cache for query | 0.000071 | 0 | 0 |
  | Opening tables | 0.000024 | 0 | 0 |
  | System lock | 0.000014 | 0 | 0 |
  | Table lock | 0.000055 | 0.001 | 0 |
  | init | 0.000036 | 0 | 0 |
  | optimizing | 0.000013 | 0 | 0 |
  | statistics | 0.000021 | 0 | 0 |
  | preparing | 0.00002 | 0 | 0 |
  | executing | 0.00001 | 0 | 0 |
  | Sending data | 0.015072 | 0.011998 | 0 |
  | end | 0.000021 | 0 | 0 |
  | query end | 0.000011 | 0 | 0 |
  | storing result in query cache | 0.00001 | 0 | 0 |
  | freeing items | 0.000018 | 0 | 0 |
  | closing tables | 0.000019 | 0 | 0 |
  | logging slow query | 0.000009 | 0 | 0 |
  +--------------------------------+----------+----------+------------+
  

  * mysql> show profile IPC for query 1;

  +--------------------------------+----------+---------------+-------------------+
  | Status | Duration | Messages_sent | Messages_received |
  +--------------------------------+----------+---------------+-------------------+
  | (initialization) | 0.000007 | 0 | 0 |
  | checking query cache for query | 0.000071 | 0 | 0 |
  | Opening tables | 0.000024 | 0 | 0 |
  | System lock | 0.000014 | 0 | 0 |
  | Table lock | 0.000055 | 0 | 0 |
  | init | 0.000036 | 0 | 0 |
  | optimizing | 0.000013 | 0 | 0 |
  | statistics | 0.000021 | 0 | 0 |
  | preparing | 0.00002 | 0 | 0 |
  | executing | 0.00001 | 0 | 0 |
  | Sending data | 0.015072 | 0 | 0 |
  | end | 0.000021 | 0 | 0 |
  | query end | 0.000011 | 0 | 0 |
  | storing result in query cache | 0.00001 | 0 | 0 |
  | freeing items | 0.000018 | 0 | 0 |
  | closing tables | 0.000019 | 0 | 0 |
  | logging slow query | 0.000009 | 0 | 0 |
  +--------------------------------+----------+---------------+-------------------+
  

其它屬性列表

  * ALL - displays all information
  * BLOCK IO - displays counts for block input and output operations
  * CONTEXT SWITCHES - displays counts for voluntary and involuntary context switches
  * IPC - displays counts for messages sent and received
  * MEMORY - is not currently implemented
  * PAGE FAULTS - displays counts for major and minor page faults
  * SOURCE - displays the names of functions from the source code, together with the name and line number of the file in which the function occurs
  * SWAPS - displays swap counts

設定 Profiling 存的 Size

  * mysql> show variables where variable_name='profiling_history_size'; # 預設是 15筆

關閉

  * mysql> set profiling=0
----------------------------------------
mysql> set @start_time:=unix_timestamp();
Query OK, 0 rows affected (0.00 sec)

mysql> select 1+1; #这里写您要执行的语句(可以多条用;隔开)
+-----+
| 1+1 |
+-----+
| 2 |
+-----+
1 row in set (0.00 sec)

mysql> select sec_to_time(unix_timestamp()-@start_time) as passed_time;
+-------------+
| passed_time |
+-------------+
| 00:01:01 |
+-------------+
1 row in set (0.00 sec)


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