Note
- For V4.3.x, this view is available starting with V4.3.5.
- For V4.2.x, this view is available starting with V4.2.2.
Purpose
The DBA_WR_EVENT_NAME view displays the names of tenant-level wait events that have been persisted.
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 wait event parameter 1. |
| PARAMETER2 | varchar(64) | YES | The name of wait event parameter 2. |
| PARAMETER3 | varchar(64) | YES | The name of wait event parameter 3. |
| WAIT_CLASS_ID | bigint(20) | YES | The ID of the class to which the wait event belongs. |
| WAIT_CLASS | varchar(64) | YES | The name of the class to which the wait event belongs. |
The WAIT_CLASS column in the view contains the names of wait event classes and the corresponding wait event IDs, as shown in the following table.
| Wait event class name | Wait event ID | Description |
|---|---|---|
| OTHER | 100 | A wait event that does not belong to any other class. |
| APPLICATION | 101 | A wait event caused by client-side code. |
| CONFIGURATION | 102 | A wait event caused by insufficient database or instance resources. |
| ADMINISTRATIVE | 103 | A wait event caused by a database administrator command. |
| CONCURRENCY | 104 | A wait event for internal database resources. |
| COMMIT | 105 | A wait event related to log submission. |
| IDLE | 106 | A wait event for an inactive session. |
| NETWORK | 107 | A wait event related to network communication. |
| USER_IO | 108 | A wait event for user I/O. |
| SYSTEM_IO | 109 | A wait event for background process I/O. |
| CLUSTER | 111 | A wait event related to a cluster. |
Sample query
Query the names of tenant-level wait events that have been persisted and display the first 10 records.
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