Note
- For OceanBase Database V4.3.x, this view is introduced in V4.3.5.
- For OceanBase Database V4.2.x, this view is introduced in V4.2.2.
Purpose
The DBA_WR_EVENT_NAME view displays the names of tenant-level wait events persisted in the current tenant.
Columns
Column |
Type |
Nullable? |
Description |
|---|---|---|---|
| EVENT_ID | bigint(20) | NO | The ID of the wait event. |
| EVENT_NAME | varchar(64) | YES | The name of the wait event. |
| PARAMETER1 | varchar(64) | YES | The name of parameter 1. |
| PARAMETER2 | varchar(64) | YES | The name of parameter 2. |
| PARAMETER3 | varchar(64) | YES | The name of parameter 3. |
| WAIT_CLASS_ID | bigint(20) | YES | The ID of the wait event category. |
| WAIT_CLASS | varchar(64) | YES | The name of the wait event category. |
The following table describes the wait event categories in the WAIT_CLASS column. | Wait event category | Wait event ID | Description | |------|----|------| | OTHER | 100 | Wait events that do not belong to other categories | | APPLICATION | 101 | Wait events caused by client-side code | | CONFIGURATION | 102 | Wait events caused by insufficient configurations of database or instance resources | | ADMINISTRATIVE | 103 | Wait events caused by user wait due to 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 inactive 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 by background processes |
| CLUSTER | 111 | Wait events related to clusters|
Sample query
obclient [oceanbase]> SELECT * FROM oceanbase.DBA_WR_EVENT_NAME LIMIT 10;
The query result is as follows:
+----------+-----------------------------------+------------+------------+------------+---------------+-------------+
| EVENT_ID | EVENT_NAME | PARAMETER1 | PARAMETER2 | PARAMETER3 | WAIT_CLASS_ID | WAIT_CLASS |
+----------+-----------------------------------+------------+------------+------------+---------------+-------------+
| 0 | latch: latch wait queue lock wait | address | number | tries | 104 | CONCURRENCY |
| 1 | latch: default spin lock wait | address | number | tries | 104 | CONCURRENCY |
| 2 | latch: default spin rwlock wait | address | number | tries | 104 | CONCURRENCY |
| 3 | latch: default mutex wait | address | number | tries | 104 | CONCURRENCY |
| 4 | latch: kv cache bucket latch wait | address | number | tries | 104 | CONCURRENCY |
| 5 | latch: time wheel task latch wait | address | number | tries | 104 | CONCURRENCY |
| 7 | latch: election latch wait | address | number | tries | 104 | CONCURRENCY |
| 8 | latch: trans ctx latch wait | address | number | tries | 104 | CONCURRENCY |
| 14 | latch: clog reconfirm latch wait | address | number | tries | 104 | CONCURRENCY |
| 17 | latch: clog task latch wait | address | number | tries | 104 | CONCURRENCY |
+----------+-----------------------------------+------------+------------+------------+---------------+-------------+
10 rows in set