In MariaDB, an extra column '<<fixed>>TIME_MS<</fixed>>' has been added to the
<<fixed>>INFORMATION_SCHEMA.PROCESSLIST<</fixed>> table, as well as to the
output of <<fixed>>SHOW FULL PROCESSLIST<</fixed>>. This column shows the same
information as the column '<<fixed>>TIME<</fixed>>', but in units of
milliseconds with microsecond precision (the unit and precision of the
'<<fixed>>TIME<</fixed>>' column is one second).
The value displayed in the '<<fixed>>TIME<</fixed>>' and
'<<fixed>>TIME_MS<</fixed>>' columns is the period of time that the given
thread has been in its current state. Thus it can be used to check for example
how long a thread has been executing the current query, or for how long it has
been idle.
<<code>>
MariaDB [(none)]> select id, time, time_ms, command, state
-> from information_schema.processlist, (select sleep(2)) t;
+----+------+----------+---------+-----------+
| id | time | time_ms | command | state |
+----+------+----------+---------+-----------+
| 37 | 2 | 2000.493 | Query | executing |
+----+------+----------+---------+-----------+
1 row in set (2.00 sec)
<</code>>
Note that as a difference to MySQL, in MariaDB the '<<fixed>>TIME<</fixed>>'
column (and also the '<<fixed>>TIME_MS<</fixed>>' column) are not affected by
any setting of <<fixed>>@TIMESTAMP<</fixed>>. This means that it can be
reliably used also for threads that change <<fixed>>@TIMESTAMP<</fixed>> (such
as the replication SQL thread). See also mybug:22047.
As a consequence of this, the '<<fixed>>TIME<</fixed>>' column of
<<fixed>>SHOW FULL PROCESSLIST<</fixed>> and
<<fixed>>INFORMATION_SCHEMA.PROCESSLIST<</fixed>> can not be used to determine
if a slave is lagging behind. For this, use instead the
<<fixed>>Seconds_Behind_Master<</fixed>> column in the output of
<<fixed>>SHOW SLAVE STATUS<</fixed>>.
The addition of the TIME_MS column is based on the microsec_process patch,
developed by [[http://www.percona.com/|Percona]].
