mysql的sql性能分析器(2)

 
mysql> show profiles;
+----------+------------+-------------------------------------+
| Query_ID | Duration   | Query                               |
+----------+------------+-------------------------------------+
|        1 | 0.00382400 | select @@profiling                  |
|        2 | 0.00268500 | create table t5 as select * from t1 |
|        3 | 0.00017200 | SELECT DATABASE()                   |
|        4 | 0.01985400 | show databases                      |
|        5 | 0.00018900 | show tables                         |
|        6 | 0.06225200 | create table t5 as select * from t1 |
|        7 | 0.00368800 | select count(*) from t5             |
|        8 | 0.00322200 | select count(*) from t5             |
+----------+------------+-------------------------------------+
8 rows in set (0.01 sec)
 
mysql>
mysql> show profile for query 7;
+--------------------+----------+
| Status             | Duration |
+--------------------+----------+
| (initialization)   | 0.000414 |
| Opening tables     | 0.000599 |
| System lock        | 0.000254 |
| Table lock         | 0.000175 |
| init               | 0.000052 |
| optimizing         | 0.00001  |
| executing          | 0.002107 |
| end                | 0.000042 |
| query end          | 0.000005 |
| freeing items      | 0.000014 |
| closing tables     | 0.000011 |
| logging slow query | 0.000005 |
+--------------------+----------+