通過(guò)profile命令來(lái)查看當(dāng)前最主要的耗費(fèi)時(shí)間的步驟。

mysql>?select?count(1)?from?t1;
+----------+
|?count(1)?|
+----------+
|????????1?|
+----------+
1?row?in?set?(0.11?sec)

mysql>?show?profiles;
+----------+------------+-------------------------+
|?Query_ID?|?Duration???|?Query???????????????????|
+----------+------------+-------------------------+
|????????1?|?0.00123300?|?show?databases??????????|
|????????2?|?0.00016775?|?SELECT?DATABASE()???????|
|????????3?|?0.00092900?|?show?databases??????????|
|????????4?|?0.00122325?|?show?tables?????????????|
|????????5?|?0.00134250?|?show?tables?????????????|
|????????6?|?0.11396400?|?select?count(1)?from?t1?|
+----------+------------+-------------------------+
6?rows?in?set,?1?warning?(0.00?sec)

mysql>?show?profile?for?query?6;?
+--------------------------------+----------+
|?Status?????????????????????????|?Duration?|
+--------------------------------+----------+
|?starting???????????????????????|?0.000089?|
|?Executing?hook?on?transaction??|?0.000013?|
|?starting???????????????????????|?0.000011?|
|?checking?permissions???????????|?0.000008?|
|?Opening?tables?????????????????|?0.000040?|
|?init???????????????????????????|?0.000015?|
|?System?lock????????????????????|?0.000015?|
|?optimizing?????????????????????|?0.000007?|
|?statistics?????????????????????|?0.000024?|
|?preparing??????????????????????|?0.000029?|
|?executing??????????????????????|?0.113622?|
|?end????????????????????????????|?0.000011?|
|?query?end??????????????????????|?0.000006?|
|?waiting?for?handler?commit?????|?0.000014?|
|?closing?tables?????????????????|?0.000013?|
|?freeing?items??????????????????|?0.000022?|
|?cleaning?up????????????????????|?0.000027?|
+--------------------------------+----------+
17?rows?in?set,?1?warning?(0.00?sec)

mysql>?select?state,sum(duration)?as?total_r?,?round(100*sum(duration)/(select?sum(duration)?from?information_schema.profiling?where?query_id=6),2)?as?pct_r,count(*)?as?calls,sum(duration)/count(*)?as?'R/Call'?from?information_schema.profiling?where?query_id?group?by?state?order?by?total_r?desc;
+--------------------------------+----------+--------+-------+--------------+
|?state??????????????????????????|?total_r??|?pct_r??|?calls?|?R/Call???????|
+--------------------------------+----------+--------+-------+--------------+
|?executing??????????????????????|?0.114058?|?100.08?|?????6?|?0.0190096667?|
|?Opening?tables?????????????????|?0.001226?|???1.08?|?????6?|?0.0002043333?|
|?checking?permissions???????????|?0.000852?|???0.75?|????56?|?0.0000152143?|
|?starting???????????????????????|?0.000692?|???0.61?|?????8?|?0.0000865000?|
|?Creating?tmp?table?????????????|?0.000524?|???0.46?|?????4?|?0.0001310000?|
|?init???????????????????????????|?0.000410?|???0.36?|?????6?|?0.0000683333?|
|?statistics?????????????????????|?0.000361?|???0.32?|?????5?|?0.0000722000?|
|?preparing??????????????????????|?0.000165?|???0.14?|?????5?|?0.0000330000?|
|?freeing?items??????????????????|?0.000138?|???0.12?|?????7?|?0.0000197143?|
|?cleaning?up????????????????????|?0.000108?|???0.09?|?????7?|?0.0000154286?|
|?optimizing?????????????????????|?0.000092?|???0.08?|?????6?|?0.0000153333?|
|?waiting?for?handler?commit?????|?0.000084?|???0.07?|?????9?|?0.0000093333?|
|?System?lock????????????????????|?0.000079?|???0.07?|?????5?|?0.0000158000?|
|?closing?tables?????????????????|?0.000067?|???0.06?|?????6?|?0.0000111667?|
|?query?end??????????????????????|?0.000039?|???0.03?|?????6?|?0.0000065000?|
|?end????????????????????????????|?0.000035?|???0.03?|?????6?|?0.0000058333?|
|?removing?tmp?table?????????????|?0.000018?|???0.02?|?????4?|?0.0000045000?|
|?Executing?hook?on?transaction??|?0.000013?|???0.01?|?????1?|?0.0000130000?|
+--------------------------------+----------+--------+-------+--------------+
18?rows?in?set,?2?warnings?(0.00?sec)

profile還支持查看all、cpu、block io、content switch、page faults等明細(xì)類型，例如查看上述語(yǔ)句在CPU資源上消耗的時(shí)間：

show profile cpu ?for query 6；文章來(lái)源地址http://www.zghlxwxcb.cn/news/detail-854803.html

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