標籤:oracle隊列 enqueue
本文參照oracle11gr2官方文檔《Oracle? Database Reference11g Release 2 (11.2)》
隊列定義:oracle隊列存在共用記憶體中串列訪問資料庫資源的鎖。它產生於一次回話或者一個事物。
隊列尋找:在系統資料庫詞典視圖 DBA_LOCK_INTERNAL和DBA_LOCK的Lock_type那一列。
產生原因:oracle資源唯一地標識一個對象,可以被不同的會話執行個體之間在一個執行個體(本地資源)或(全球資源)。每個會話試圖鎖定資源所以就會產生隊列
隊列名稱:(前面是簡稱,即資料庫詞典查出的內容,後面是解釋)
?BL, Buffer Cache Management
?BR, Backup/Restore
?CF, Controlfile Transaction
?CI, Cross-instance Call Invocation
?CU, Bind Enqueue
?DF, Datafile
?DL, Direct Loader Index Creation
?DM, Database Mount
?DR, Distributed Recovery Process
?DW, SecureFiles
?DX, Distributed Transaction
?FP, File Object
?FS, File Set
?HW, High-Water Lock
?IN, Instance Number
?IR, Instance Recovery
?IS, Instance State
?IV, Library Cache Invalidation
?JI, Enqueue used during AJV snapshot refresh
?JQ, Job Queue
?KK, Redo Log "Kick"
?KP, contention in Oracle Data Pump startup and shutdown processes
?KO, Multiple Object Checkpoint
?L[A-P], Library Cache Lock
?LS, Log Start or Switch
?MM, Mount Definition
?MR, Media Recovery
?N[A-Z], Library Cache Pin
?PE, ALTER SYSTEM SET PARAMETER = VALUE
?PF, Password File
?PI, Parallel Slaves
?PR, Process Startup
?PS, Parallel Slave Synchronization
?Q[A-Z], Row Cache
?RO, Object Reuse
?RT, Redo Thread
?RW, Row Wait
?SC, System Commit Number
?SM, SMON
?SN, Sequence Number
?SQ, Sequence Number Enqueue
?SR, Synchronized Replication
?SS, Sort Segment
?ST, Space Management Transaction
?SV, Sequence Number Value
?TA, Transaction Recovery
?TC, Thread Checkpoint
?TE, Extend Table
?TM, DML Enqueue
?TO, Temporary Table Object Enqueue
?TS, Temporary Segment (also TableSpace)
?TT, Temporary Table
?TX, Transaction
?UL, User-defined Locks
?UN, User Name
?US, Undo Segment, Serialization
?WL, Being Written Redo Log
?XA, Instance Attribute Lock
?XI, Instance Registration Lock
前面有一篇文檔用到了隊列,當時沒做過多得解釋,所以專門補充了一下
等待事件:http://blog.csdn.net/jacson_bai/article/details/38323821