Note
- The view was introduced in OceanBase Database V4.3.5 for V4.3.x.
- The view was introduced in OceanBase Database V4.2.2 for V4.2.x.
Purpose
The CDB_WR_EVENT_NAME view displays the names of all tenant-level wait events after they are persisted.
Columns
| Column | Type | Nullable? | Description |
|---|---|---|---|
| TENANT_ID | bigint(20) | NO | Tenant ID |
| CLUSTER_ID | bigint(20) | NO | Cluster ID |
| EVENT_ID | bigint(20) | NO | Wait event ID |
| EVENT_NAME | varchar(64) | YES | Wait event name |
| PARAMETER1 | varchar(64) | YES | Name of wait event parameter 1 |
| PARAMETER2 | varchar(64) | YES | Name of wait event parameter 2 |
| PARAMETER3 | varchar(64) | YES | Name of wait event parameter 3 |
| WAIT_CLASS_ID | bigint(20) | YES | ID of the wait event category |
| WAIT_CLASS | varchar(64) | YES | Name of the wait event category |
The following table describes the wait event categories and their corresponding wait event IDs in the WAIT_CLASS column of the view. | Wait event category | Wait event ID | Description | |------|----|------| | OTHER | 100 | Wait events that do not fall into any other category. | | APPLICATION | 101 | Wait events caused by client-side code. | | CONFIGURATION | 102 | Wait events caused by insufficient resource configuration of the database or instance. | | ADMINISTRATIVE | 103 | Wait events caused by commands entered by the database administrator. | | CONCURRENCY | 104 | Wait events caused by waiting for internal database resources. | | COMMIT | 105 | Wait events related to log commit. | | IDLE | 106 | Wait events caused by idle sessions waiting for tasks. | | NETWORK | 107 | Wait events related to network communication. | | USER_IO | 108 | Wait events caused by waiting for user I/O. | | SYSTEM_IO | 109 | Wait events caused by waiting for I/O from background processes. |
| CLUSTER | 111 | Wait events related to clusters.|
Sample query
obclient [oceanbase]> SELECT * FROM oceanbase.CDB_WR_EVENT_NAME WHERE TENANT_ID= 1004 LIMIT 10;
The sample query result is as follows:
+-----------+------------+----------+-----------------------------------+------------+------------+------------+---------------+-------------+
| TENANT_ID | CLUSTER_ID | EVENT_ID | EVENT_NAME | PARAMETER1 | PARAMETER2 | PARAMETER3 | WAIT_CLASS_ID | WAIT_CLASS |
+-----------+------------+----------+-----------------------------------+------------+------------+------------+---------------+-------------+
| 1004 | 10001 | 0 | latch: latch wait queue lock wait | address | number | tries | 104 | CONCURRENCY |
| 1004 | 10001 | 1 | latch: default spin lock wait | address | number | tries | 104 | CONCURRENCY |
| 1004 | 10001 | 2 | latch: default spin rwlock wait | address | number | tries | 104 | CONCURRENCY |
| 1004 | 10001 | 3 | latch: default mutex wait | address | number | tries | 104 | CONCURRENCY |
| 1004 | 10001 | 4 | latch: kv cache bucket latch wait | address | number | tries | 104 | CONCURRENCY |
| 1004 | 10001 | 5 | latch: time wheel task latch wait | address | number | tries | 104 | CONCURRENCY |
| 1004 | 10001 | 7 | latch: election latch wait | address | number | tries | 104 | CONCURRENCY |
| 1004 | 10001 | 8 | latch: trans ctx latch wait | address | number | tries | 104 | CONCURRENCY |
| 1004 | 10001 | 14 | latch: clog reconfirm latch wait | address | number | tries | 104 | CONCURRENCY |
| 1004 | 10001 | 17 | latch: clog task latch wait | address | number | tries | 104 | CONCURRENCY |
+-----------+------------+----------+-----------------------------------+------------+------------+------------+---------------+-------------+
10 rows in set