表X-XX
| Wait Event Type |
Wait Event Name |
Description |
|
Lock[1] |
relation |
Waiting to acquire a lock on a relation. |
| extend |
Waiting to extend a relation. |
|
| page |
Waiting to acquire a lock on page of a relation. |
|
| tuple |
Waiting to acquire a lock on a tuple. |
|
| transactionid |
Waiting for a transaction to finish. |
|
| virtualxid |
Waiting to acquire a virtual xid lock. |
|
| speculative token |
Waiting to acquire a speculative insertion lock. |
|
| object |
Waiting to acquire a lock on a non-relation database object. |
|
| userlock |
Waiting to acquire a userlock. |
|
| advisory |
Waiting to acquire an advisory user lock. |
|
| BufferPin[2] |
BufferPin |
Waiting to acquire a pin on a buffer. |
[1] The backend is waiting for a heavyweight lock. Heavyweight locks, also known as lock manager locks or simply locks, primarily protect SQL-visible objects such as tables. However, they are also used to ensure mutual exclusion for certain internal operations such as relation extension. wait_event will identify the type of lock awaited.
[2] The server process is waiting to access to a data buffer during a period when no other process can be examining that buffer. Buffer pin waits can be protracted if another process holds an open cursor which last read data from the buffer in question