Process List¶
This page describes Percona changes to both the standard MySQL SHOW PROCESSLIST
command and the standard MySQL INFORMATION_SCHEMA
table PROCESSLIST
.
The changes that have been made as of version 5.5 of the server are:
SHOW PROCESSLIST
command:
- added columns
ROWS_EXAMINED
,ROWS_SENT
, andROWS_READ
PROCESSLIST
table:
- added columns
TIME_MS
,ROWS_EXAMINED
,ROWS_SENT
, andROWS_READ
Version Specific Information¶
5.5.10-20.1
:
- Added columns
ROWS_EXAMINED
,ROWS_SENT
, andROWS_READ
toSHOW PROCESSLIST
command.- Added columns
ROWS_EXAMINED
,ROWS_SENT
, andROWS_READ
toPROCESSLIST
table.
INFORMATION_SCHEMA Tables¶
-
table
INFORMATION_SCHEMA.
PROCESSLIST
¶ This table implements modifications to the standard MySQL
INFORMATION_SCHEMA
tablePROCESSLIST
.Columns: - ID – The connection identifier.
- USER – The MySQL user who issued the statement.
- HOST – The host name of the client issuing the statement.
- DB – The default database, if one is selected, otherwise NULL.
- COMMAND – The type of command the thread is executing.
- TIME – The time in seconds that the thread has been in its current state.
- STATE – An action, event, or state that indicates what the thread is doing.
- INFO – The statement that the thread is executing, or NULL if it is not executing any statement.
- TIME_MS – The time in milliseconds that the thread has been in its current state.
- ROWS_EXAMINED – The number of rows examined by the statement being executed (NOTE: This column is not updated for each examined row so it does not necessarily show an up-to-date value while the statement is executing. It only shows a correct value after the statement has completed.).
- ROWS_SENT – The number of rows sent by the statement being executed.
- ROWS_READ – The number of rows read by the statement being executed.
Example Output¶
SHOW PROCESSLIST
Command:
mysql> show processlist;
+------+-----------+-----------+--------+---------+------+------------+----------------------------------------------+-----------+---------------+-----------+
| Id | User | Host | db | Command | Time | State | Info | ROWS_SENT | ROWS_EXAMINED | ROWS_READ |
+------+-----------+-----------+--------+---------+------+------------+----------------------------------------------+-----------+---------------+-----------+
| 2 | root | localhost | test | Query | 0 | NULL | SHOW PROCESSLIST | 0 | 0 | 1 |
| 14 | root | localhost | test | Query | 0 | User lock | SELECT GET_LOCK(``t``,1000) | 0 | 0 | 1 |
+------+-----------+-----------+--------+---------+------+------------+----------------------------------------------+-----------+---------------+-----------+
Table PROCESSLIST
:
mysql> select * from information_schema.PROCESSLIST;
+------+-----------+-----------+--------+---------+------+------------+----------------------------------------------+----------+---------------+-----------+-----------+
| ID | USER | HOST | DB | COMMAND | TIME | STATE | INFO | TIME_MS | ROWS_EXAMINED | ROWS_SENT | ROWS_READ |
+------+-----------+-----------+--------+---------+------+------------+----------------------------------------------+----------+---------------+-----------+-----------+
| 14 | root | localhost | test | Query | 0 | User lock | SELECT GET_LOCK(``t``,1000) | 1 | 0 | 0 | 1 |
| 2 | root | localhost | test | Query | 0 | executing | SELECT * from INFORMATION_SCHEMA.PROCESSLIST | 0 | 0 | 0 | 1 |
+------+-----------+-----------+--------+---------+------+------------+----------------------------------------------+----------+---------------+-----------+-----------+
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