[20151223]enq WP - contition 代表什麼

[20151223]enq WP  - contition 代表什麼.txt

--論壇有人問這個問題，我自己也不知道，百度也沒有這方面的資訊。

http://www.itpub.net/thread-2049297-1-1.html

--其實很簡單查詢檢視：
SYS@book> select eq_name,eq_type,req_reason from v$enqueue_statistics where eq_type='WP';
EQ_NAME                                                          EQ REQ_REASON
---------------------------------------------------------------- -- ----------------------------------------------------------------
AWR Purge                                                        WP contention

--瞭解其他也可以查詢，例子：

SYS@book> select eq_name,eq_type,req_reason from v$enqueue_statistics where eq_type='HW';
EQ_NAME                                                          EQ REQ_REASON
---------------------------------------------------------------- -- ----------------------------------------------------------------
Segment High Water Mark                                          HW contention

SYS@book> select eq_name,eq_type,req_reason from v$enqueue_statistics where eq_type='TX';
EQ_NAME                                                          EQ REQ_REASON
---------------------------------------------------------------- -- ----------------------------------------------------------------
Transaction                                                      TX index contention
Transaction                                                      TX allocate ITL entry
Transaction                                                      TX row lock contention
Transaction                                                      TX contention

--自己做一個記錄。