Oracle queue type

Oracle queue type

For more information, see the official oracle11gr2 documentation 《Oracle? Database Reference11GRelease 2 (11.2)"

Queue definition:The oracle queue has a shared memory for serial access to database resources.Lock. It is produced by a session or a thing.

Queue search: In the system database dictionary view, the Lock_type column of DBA_LOCK_INTERNAL and DBA_LOCK.

Cause: An oracle resource uniquely identifies an object, which can be located in one instance (local resource) or (Global Resource) between different session instances ). Every session tries to lock resources, so a queue is generated.

Queue name(Abbreviation: The content found in the database dictionary, which is explained later)

? 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

I used the queue in the previous article, but I didn't have much explanation at the time, so I made a special supplement.

Wait event: http://blog.csdn.net/jacson_bai/article/details/38323821