MySQL 显示SQL语句执行时间的代码

这篇文章主要为大家详细介绍了MySQL 显示SQL语句执行时间的代码，具有一定的参考价值，可以用来参考一下。

对此感兴趣的朋友，看看idc笔记做的技术笔记！

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 showmysql> 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) [test]> 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 informationBLOCK IO - displays counts for block input and output operationsCONTEXT SWITCHES - displays counts for voluntary and involuntary context switchesIPC - displays counts for messages sent and receivedMEMORY - is not currently implementedPAGE FAULTS - displays counts for major and minor page faultsSOURCE - displays the names of functions from the source code, together with the name and line number of the file in which the function occursSWAPS - displays swap counts設定 Profiling 存的 Sizemysql> show variables where variable_name='profiling_history_size'; # 預設是 15筆關閉mysql> set profiling=0;

注：关于MySQL 显示SQL语句执行时间的代码的内容就先介绍到这里，更多相关文章的可以留意