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.
使用方法如下：
1.启动
- 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.
2.查询
- 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.
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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
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查詢各執行階段花費多少時間
- mysql> show profile for query 1; # Query ID = 1
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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
- mysql> show profile IPC for query 1;
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
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設定 Profiling 存的 Size
- mysql> show variables where variable_name='profiling_history_size'; # 預設是 15筆
3.关闭
- mysql> set profiling=0;