wait event

In AWR, we may see the following information:     Here, the read byother session takes a lot of time.   Read by other session is described as follows: When informationis requested from the database, Oracle will first read the data from disk beyond

There are many ways to view the SQL Execution Plan. 10046 events are one of them. different from other SQL Execution plans, when we encounter complicated SQL statements, we can track SQL statements through 10046 to obtain the logical reads of each

SQL tracking and tkprof usage, SQL tracking tkprof usageBrief Introduction In oracle databases, awr is a report on the overall load and running status of the database system. However, when the system load is normal, and the client executes some

Mutex (test), mutexHow to Use Mutex for cursor sharing Kks uses mutex to protect a series of operations based on parent cursor parent and child cursor For the parent cursor operation of the parent cursor: Different wait events are generated based

There are two origins: 1) Frequent redo records2) server process generates a small amount of data each time.   If the redo log file generated each time requires a large number of highly concurrent SPSS to write the redo log file, there are two

View wait events -- V $ session_wait: P1, P2, and P3 indicate the specific meaning of the wait event. If the wait event is dB file scattered read, P1 = file_id/P2 = block_id/P3 = blocks, then use dba_extents. Determine the hotspot object.-- If it is

There are two origins:1) Frequent redo records2) server process generates a small amount of data each time. If the redo log file generated each time requires a large number of highly concurrent SPSS to write the redo log file, there are two problems:

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

This wait event occurs on top 5 of a customer's 10.2.0.5 database. In fact, this StreamsAQ: qmncoordinatorwaitingforslavetostart wait reason in addition to the parameter settings unreasonable, the main reason is that the database is too idle:

Background: The user reports that the database runs slowly, but the database returns to normal again when it is viewed. The AWR report for the past period of time is decisively viewed. The AWR report information is as follows: Background: The user

Overview Wait events can be divided into two main categories, namely, Idle (IDLE) Wait events and non idle (non-idle) wait events. 1). Idle Wait Event Oracle is waiting for some kind of work, not paying too much attention to this part of the

0046 Event OverviewOracle's 10046 event tracks the SQL statements executed by the application and gets its number of resolutions. Number of executions, CPU usage, and so on. This is very useful for us to analyze and locate database performance

Original: 2-year summary of SQL Server DBA tuning2 years SQL Server DBA Summary of tuningWhen I was 2 DBA I felt that there was something that needed to be shared with everyone to discuss the book first.Book List1. "In-depth analysis of SQL Server 20

　　Elapse time is two snap intervals, which is equivalent to a sampling differenceDB time:db time= CPU times + wait time (not including idle wait) (non-background process) It's just that the DB is when the logged server spends its hours on database

Oracle Automatic Performance statistics?? Efficient diagnosis of performance problems, need to provide complete statistics available, like the doctor to the patient's palpation, to be able to correctly diagnose, and then prescribe the corresponding

Tkprof is a command-line tool provided by Oracle, the primary role is to convert the original trace file to a formatted text file, the simplest way to use the following:Tkprof LY_ORA_128636.TRC Ly_ora_128636.txtTkprof has many parameters, and in

Index overviewThe index, like a table, also belongs to a segment (segment). It contains the user's data, which takes up disk space as well as the table. However, the data stored in the index is very different from the data storage form in the table.

Here is a fragment of the trace file that represents a SQL execution process, and a trace file consists of a number of such fragments:parsing in CURSOR #4 len=135 dep=1 uid=0 oct=3 lid=0 tim=777069789359 hv=1115215392 ad= ' 33 e7e384 ' Select/*+

When analyzing the event enq TX row lock contention Analysis in the Oracle database performance report AWRRPT, it is found that the top 5 tasks waiting for the event first are enq: TX-row lock contention. Www.2cto.com Rpt code Top 5 Timed Events

First, let's clarify one thing: cursorpinswaitonx is the symptom (result), not the root cause. Mutexrelatedwaiteventcursor: pinSwaitonX general cause: frequent hard parsing (High Resolution time. It is critical to find out the reasons for high