Information Schema PROCESSLIST Table
The Information Schema PROCESSLIST table contains information about running threads.
It contains the following columns:
| Column | Description | Added |
|---|---|---|
| ID | Connection identifier. | |
| USER | MariaDB User. | |
| HOST | Connecting host. | |
| DB | Default database, or NULL if none. | |
| COMMAND | Type of command running, corresponding to the Com_ status variables. | |
| TIME | Seconds that the thread has been in its current state. | |
| STATE | Current state of the thread. | |
| INFO | Statement the thread is executing, or NULL if none. | |
| TIME_MS | Time in milliseconds with microsecond precision that the thread has been in its current state (see more). | MariaDB 5.1 |
| STAGE | The stage the process is currently in. | MariaDB 5.3 |
| MAX_STAGE | The maximum number of stages. | MariaDB 5.3 |
| PROGRESS | The progress of the process within the current stage (0-100%). | MariaDB 5.3 |
| MEMORY_USED | Memory used by the thread. | MariaDB 10.0.1 |
| EXAMINED_ROWS | Rows examined by the thread. | MariaDB 10.0.1 |
| QUERY_ID | Query ID. | MariaDB 10.0.5 |
Similar information can also be returned with the SHOW [FULL] PROCESSLIST statement, or the mysqladmin processlist command.
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.
Note that the PROGRESS field from the information schema, and the PROGRESS field from SHOW PROCESSLIST display different results. SHOW PROCESSLIST shows the total progress, while the information schema shows the progress for the current stage only.. To retrieve a similar "total" Progress value from INFORMATION_SCHEMA.PROCESSLIST as the one from SHOW PROCESSLIST, use
SELECT CASE WHEN Max_Stage < 2 THEN Progress ELSE (Stage-1)/Max_Stage*100+Progress/Max_Stage END AS Progress FROM INFORMATION_SCHEMA.PROCESSLIST;
