wait event

Summarize Oracle system views and table Daquan:Dba_ opening .....Dba_users Database user InformationDba_segments Table Segment InformationDba_extents Data Area InformationDba_objects Database object InformationDba_tablespaces database table Space

" Guide "When talking to a friend or colleague about the MySQL query cache function, the individual likes to compare the query cache function to the Litchi , is very nutritious things, but once eat too much, it is easy to get angry and nosebleeds,

Before simply writing a 10046-event introduction to the article http://hbxztc.blog.51cto.com/1587495/1898624, of course, collecting 10046 trace is not the ultimate goal, able to read and analyze 10046 Trace and then analyze the performance problem

Background knowledge:10046 events can be divided into 4 levels according to the content of the collected information:Level 1: function equivalent to Sql_traceLevel 4: Increase the collection of binding variable information on the basis of 1Level 8:

1. Gets the SQL statement being executed, the execution time of the SQL statement, and the wait event for the SQL statement:Select A.sql_text,b.status,b.last_call_et,b.machine,b.event,b.program from V$sql a,v$session b where a.sql_id=b.sql_ Id2. Get

I. Sql_trace description1.1. In the global enable specified in the parameter file (pfile/spfile): Sql_trace =true 1.2. At the current session level, enable tracing for the current session: Alter session set Sql_trace =true; End Trace: Alter

Multithreading programming learning notes-Thread Pool (3), multithreading programming learning notes Multi-thread programming learning notes-Thread Pool (1) Multi-thread programming learning notes-Thread Pool (2)   5. Waiting for event processor and

Article Title: Analysis of missing events in the event monitoring mechanism of Linux. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded

Reading Notes db file scattered read DB, db file sequential read DB, free buffer waits, log buffer space, log file switch, log file syncThe view v $ session_wait can be used to view the current wait events of the system and the information about the

The attributes of DB2 locks are still unfamiliar to many new users who are new to DB2 databases. The following describes the attributes of DB2 locks in detail and hopes to help you. In the chapter on concurrency and isolation level, we can see that

Although LATCH is exclusive, this time is extreme, and it is unlikely to cause competition. If everyone is reading data blocks, then the bufferlock s modes are both Although LATCH is exclusive, this time is extreme and it is unlikely to cause

[In-depth analysis -- eygle] learning notes 1.2.7 diagnose and solve the primary problem of ORA-04031 error SharedPool is fundamentally only one, is the performance impact of excessive fragments. 1.2.7.1 what is a ORA-04031 error when trying to

3. database cache size We talked about how to share execution plans from the programmer's perspective. Next let's take a look at what DBA can do for the shared execution plan. First, we need to know that the execution plan of each statement is saved

SQL Performance Optimization-Methods for locating network performance problems (DEMO) and performance optimization demo Recently, my colleague from the project team told me that he encountered an SQL Performance problem. He said that there were only

  If the execution efficiency of a system is relatively low, a better method is to track user sessions and use the tkprof tool to format the output using the sorting function to find out problematic SQL statements. For example, first, use the top

OCP question analysis _ 043: buffer cache and hit rate calculation method: www.2cto.com SELECT name, (1-(physical_reads/(db_block_gets + consistent_gets) * 100 H_RATIO FROM v $ ratio; the hit rate, as the standard for measuring the performance of

To retain the Session information more effectively, Oracle10g adds a v $ session_wait_history view to record the last 10 waiting events of the Active Session. To retain the Session information more effectively, Oracle10g adds a v $

Conclusion: I. Six methods for obtaining an execution plan (the detailed steps are described in the remarks section at the beginning of each example ):1. Obtain the explain plan for statement;2. set autotrace on;3. statistics_level = all;4. Use dbms_

This article mainly introduces the pyinotify package used to monitor file systems in Python. pyinotify is based on the inotify event-driven mechanism. For more information, see What is inotify: Inotify is an event-driven notification mechanism.

1 Detailed completion port basic use1 Creating the completion portHANDLE IOCP = CreateIoCompletionPort (invalid_handle_value,null,0,0);The parameter is actually -1,0,0,0. The last parameter represents theNumberOfConcurrentThreads, which is the