SHOW PROFILES Syntax(MySql)

12.4.5.29.

SHOW PROFILES

Syntax

This section does not apply to MySQL Enterprise Server users.

SHOW PROFILE [[code]type

[,

type

] ... ]
[FOR QUERY

n

]
[LIMIT

row_count

[OFFSET

offset

]]

type

:
ALL
| BLOCK IO
| CONTEXT SWITCHES
| CPU
| IPC
| MEMORY
| PAGE FAULTS
| SOURCE
| SWAPS
[/code]
The

SHOW PROFILES

and

SHOW PROFILE

statements display profiling information that indicates resource usage for statements executed during the course of the current session.

Profiling is controlled by the

profiling

session variable, which has a default value of 0 (

OFF

). Profiling is enabled by setting

profiling

to 1 or

ON

:

mysql> [code]SET profiling = 1;

[/code]

SHOW PROFILES

displays a list of the most recent statements sent to the master. The size of the list is controlled by the

profiling_history_size

session variable, which has a default value of 15. The maximum value is 100. Setting the value to 0 has the practical effect of disabling profiling.

All statements are profiled except

SHOW PROFILES

and

SHOW PROFILE

, so you will find neither of those statements in the profile list. Malformed statements are profiled. For example,

SHOW PROFILING

is an illegal statement, and a syntax error occurs if you try to execute it, but it will show up in the profiling list.

SHOW PROFILE

displays detailed information about a single statement. Without the

FOR QUERY 
n
 clause, the output pertains to the most recently executed statement. If [code]FOR QUERY 
n
 is included, [code]SHOW PROFILE

displays information for statement

n

. The values of

n

correspond to the

Query_ID

values displayed by

SHOW PROFILES

.

The

LIMIT 
row_count
 clause may be given to limit the output to [code]row_count

rows. If

LIMIT

is given,

OFFSET 
offset
 may be added to begin the output [code]offset

rows into the full set of rows.

By default,

SHOW PROFILE

displays

Status

and

Duration

columns. The

Status

values are like the

State

values displayed by

SHOW PROCESSLIST

, althought there might be some minor differences in interpretion for the two statements for some status values (see Section 7.10, “Examining Thread Information”).

Optional

type

values may be specified to display specific additional types of information:

ALL

displays all information

BLOCK IO

displays counts for block input and output operations

CONTEXT SWITCHES

displays counts for voluntary and involuntary context switches

CPU

displays user and system CPU usage times

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

Profiling is enabled per session. When a session ends, its profiling information is lost.

mysql> [code]SELECT @@profiling;

+-------------+
| @@profiling |
+-------------+
| 0 |
+-------------+
1 row in set (0.00 sec)

mysql>

SET profiling = 1;

Query OK, 0 rows affected (0.00 sec)

mysql>

DROP TABLE IF EXISTS t1;

Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql>

CREATE TABLE T1 (id INT);

Query OK, 0 rows affected (0.01 sec)

mysql>

SHOW PROFILES;

+----------+----------+--------------------------+
| Query_ID | Duration | Query |
+----------+----------+--------------------------+
| 0 | 0.000088 | SET PROFILING = 1 |
| 1 | 0.000136 | DROP TABLE IF EXISTS t1 |
| 2 | 0.011947 | CREATE TABLE t1 (id INT) |
+----------+----------+--------------------------+
3 rows in set (0.00 sec)

mysql>

SHOW PROFILE;

+----------------------+----------+
| Status | Duration |
+----------------------+----------+
| checking permissions | 0.000040 |
| creating table | 0.000056 |
| After create | 0.011363 |
| query end | 0.000375 |
| freeing items | 0.000089 |
| logging slow query | 0.000019 |
| cleaning up | 0.000005 |
+----------------------+----------+
7 rows in set (0.00 sec)

mysql>

SHOW PROFILE FOR QUERY 1;

+--------------------+----------+
| Status | Duration |
+--------------------+----------+
| query end | 0.000107 |
| freeing items | 0.000008 |
| logging slow query | 0.000015 |
| cleaning up | 0.000006 |
+--------------------+----------+
4 rows in set (0.00 sec)

mysql>

SHOW PROFILE CPU FOR QUERY 2;

+----------------------+----------+----------+------------+
| Status | Duration | CPU_user | CPU_system |
+----------------------+----------+----------+------------+
| checking permissions | 0.000040 | 0.000038 | 0.000002 |
| creating table | 0.000056 | 0.000028 | 0.000028 |
| After create | 0.011363 | 0.000217 | 0.001571 |
| query end | 0.000375 | 0.000013 | 0.000028 |
| freeing items | 0.000089 | 0.000010 | 0.000014 |
| logging slow query | 0.000019 | 0.000009 | 0.000010 |
| cleaning up | 0.000005 | 0.000003 | 0.000002 |
+----------------------+----------+----------+------------+
7 rows in set (0.00 sec)
[/code]

Note
Profiling is only partially functional on some architectures. For values that depend on the

getrusage()

system call,

NULL

is returned on systems such as Windows that do not support the call. In addition, profiling is per process and not per thread. This means that activity on threads within the server other than your own may affect the timing information that you see.

SHOW PROFILES

and

SHOW PROFILE

were added in MySQL 5.0.37.

You can also get profiling information from the

PROFILING

table in

INFORMATION_SCHEMA

. See Section 18.17, “The

INFORMATION_SCHEMA PROFILING

Table”. For example, the following queries produce the same result:

SHOW PROFILE FOR QUERY 2;

SELECT STATE, FORMAT(DURATION, 6) AS DURATION
FROM INFORMATION_SCHEMA.PROFILING
WHERE QUERY_ID = 2 ORDER BY SEQ;