TIME_MS column in INFORMATION_SCHEMA.PROCESSLIST
In MariaDB, an extra column TIME_MS has been added to the
INFORMATION_SCHEMA.PROCESSLIST table. This column shows the same information as the column 'TIME', but in units of
milliseconds with microsecond precision (the unit and precision of the
TIME column is one second).
For details about microseconds support in MariaDB, see microseconds in MariaDB.
The value displayed in the TIME and
TIME_MS 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.
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 | +----+------+----------+---------+-----------+
Note that as a difference to MySQL, in MariaDB the TIME
column (and also the TIME_MS column) are not affected by
any setting of @TIMESTAMP. This means that it can be
reliably used also for threads that change @TIMESTAMP (such
as the replication SQL thread). See also MySQL Bug #22047.
As a consequence of this, the TIME column of
SHOW FULL PROCESSLIST and
INFORMATION_SCHEMA.PROCESSLIST can not be used to determine
if a slave is lagging behind. For this, use instead the
Seconds_Behind_Master column in the output of
SHOW SLAVE STATUS.
The addition of the TIME_MS column is based on the microsec_process patch, developed by Percona.
