wait event

GC CR Disk Read EventWhen node 1 needs to read the block in the buffer cache of Node 2 and the block contains uncommitted transactions, then node 2 's LMS process needs to roll the block back to node using the undo record 1 launch the content of

Find a way to hold the library cache lock sessionReference from:How to Find which Session is Holding a particular Library Cache Lock (document ID 122793.1)In fact, there are two ways:I.. systemstate analysisTranslation is not done here, reproduced

　　1. Active switchinga thread may voluntarily discard the use of the processor because it is in a waiting state, and Windows 2000/XP will select Tochinami a new thread to start running. Many WIN32 wait for a function call (such as Waitforsingkobject

Reading notes db file scattered read DB, db file sequential read Db,free buffer waits,log buffer space,log file Switch,log file sync We can view the current waiting events in the system and the information about the resources corresponding to the

This problem is found on a database of customer environments. At that time customers for help, the database state is not normal, connected to the database can not operate normally, and there are times wrong ORA-12537 error.

Original source: Http://www.eygle.com/statspack/statspack13.htm Enqueue is a locking mechanism for protecting shared resources. This locking mechanism protects shared resources, such as data in records, to prevent two of people from updating the

1) V$lockGiven the lock information, such as the Type field, the user type locks has 3 kinds: tm,tx,ul,system Type locks There are many, common are: Mr,rt,xr,ts and so on. We only care about TM,TX locks.When TM locks, the Id1 field represents object_

The client SQL plus requests the connection, listens to the TCP connection that accepts the client, and obtains the TNS packet sent by the client. The listening process opens the pipeline used to communicate with the child process, while fork a

View v$session_wait can be used to view the current wait events for the system and information about the resources that correspond to the wait events, thus identifying the type of bottlenecks and their objects. V$session_wait's P1, p2, and P3 tell

One, shared variables between threads: Variables in the same object (thread internal methods) classThreadTest {BOOLDone ; Static voidMain () {threadtest TT=NewThreadTest ();//Create a common instance NewThread (TT. Go)

Windows critical section, kernel event, mutex, semaphore. Critical section, kernel event, mutex, semaphore, all can complete the thread synchronization, here put their respective function call, structure definition, as well as apply the situation to

DB file Scattered read For frequently accessed tables, if an index is not indexed or an appropriate index is not established, Oracle can only scan it for a full table, resulting in a large number of waiting events. When a full table scan, the data

Design patterns of several concurrent servers under Linux1> single-threaded or single-processThe equivalent of a short link, when the accept, the start of data reception and data transmission, do not accept new connections, that is, a server, a

AWR Introduction to Performance optimization ToolsThis article mainly introduces oracle10g new awr tool, I often need to use AWR for database performance optimization and fault diagnosis in my work. AWR (Automatic workload Repository) is a new tool

Directory (?) [-] Tools Introduction Deployment RMA Configuration window platform Linux/unix platform Remote Web Management summary 1. Introduction to Tools Hostmonitor is a powerful operation and maintenance management software, can monitor Windows,

What is AWR? AWR (Automatic workload Repository) A bunch of historical energy data, placed on the Sysaux table space, AWR and Sysaux are all 10g, are the key features of Oracle tuning; About 1999 years began to develop, has been 15 years of

First, locate the database failure reason. The reason for positioning can be divided into three steps: 1, if there is an Oracle error number or alert log detailed error information, you can locate the reasons for the database failure; 2, if not, you

The example of this article describes the implementation method of the C + + encapsulated thread class. Share to everyone for your reference. The specific methods are as follows: Copy Code code as follows: Notification message to the

Tuning log switching (tuning log switches) Log switching: The LGWR process stops writing logs to the current log file, closes the log file, opens a new log file, and writes the data from the log cache to the new log file. Log switching can

cache| Solution In the afternoon, the business staff reported that any operations related to the Zzss03201281cs_no table would be hang, including Desc zzss03201281cs_no, and hang there. The first feeling was locked, so I looked at the lock Sql>