wait event

The message processing mechanism in Android relies heavily on handler. Each handler has a corresponding looper that is used to continuously remove message processing from the corresponding MessageQueue. It has always been felt that MessageQueue

Recent project team colleagues told me that there was a SQL performance problem, he said the entire table has only 69 records, client execution cost two minutes, very unscientific. I helped analyze the cause and get it resolved. The following small

The effect of high water level and the performance of large concurrent inserts The rule summary of finding available blocks when inserting data blocks: High water level and low high water level: the state of the data blocks existing between the

Statspack 10 items that must be viewed in the output result 1, load between files (load profile) 2, instance efficiency click Rate (Instance efficiency hit ratios) 3, the first 5 waiting events (Top 5) 4, Waiting for events (wait event) 5.

You can use event objects to transmit signals between threads, represented by MFC's cevent. There are two states of an event object: The signal State and the non signal state. A thread can monitor events in a signal state to complete the operation

Proactor and reactor in Aces Ace_select_reactor is the default reactor implementation that is used by all platforms except Windows and will eventually wait with the Select () system function on those systems. Ace_wfmo_reactor on Windows is the

Overview The basis of a multi-channel program operating system. By switching CPUs between processes, the operating system can increase the throughput rate of the computer.For single-processor systems, only one process is allowed to run at a time:

After completing this chapter, you will learn: 1. Create a specific event handler using the Handleextenalevent activity 2. Use delay activities in your workflow 3. Use EventDriven activities in your workflow 4. Use listen activities in your

This time we mainly explain the Oracle 10053 events and experiments, many friends may not be very familiar with this event, because in the daily transport dimension use not a lot. Oracle 10046 and 10053 are unofficial trace SQL methods that are not

"Oracle------Redo"Redo log files (redo log file) are critical to the database, they are the transaction logs of the database;The Oracle database maintains two types of redo log files: An online redo log file (redo) and an archive redo log file

Deep understanding of Oracle RAC 12cJump to: Navigation, search Directory 1 Overview 2 Cluster parts management and fault diagnosis 3 Operational Practices 4 new Features 5 Storage and ASM 6

1. Viewing Active session Information[SQL] View plain copySELECT *From V$sessionWHERE USERNAME is not NULLand STATUS = ' ACTIVE 'ORDER by Logon_time, SID;Note: status is used to determine session stateActive: Executing SQL statement (waiting

With detailed 10046 trace discovery, a large number of IO waits are distributed on the following data files:Misses in library cache during parse:0Elapsed times include waiting on following events:Event waited on Times Max. Wait Total waited----------

1: Check V$db_object_cacheSELECT * from V$db_object_cache WHERE name= ' cux_oe_order_rpt_pkg ' and locks!= ' 0 ';Note: Cux_oe_order_rpt_pkg is the name of the stored procedure.Discover locks=22: Find the SID value by objectSelect/*+ rule*/SID from

MySQL turn on slow query log MySQL accelerated query speed of a unique weapon: query cache on the MySQL query cache from five angles for detailed analysis: How to query cache, how to configure, how to maintain, how to determine the performance of

The first step: the client sends the statement to the server-side executionWhen we execute the SQL statement on the client, the client sends the SQL statement to the server side, allowing the server-side process to process the statement. That is,

Introduction: The feature of Oracle parallelism has not been much of a concern in the past. A few days ago a brother encountered a problem, just let me think this thing still has a lot to pay attention to places, it is necessary to carefully

1. How to view the definition of sequence2.dba_sequences definition of related words3. How to Modify sequence*************************************************************************************************************** *****************************

At noon, we produce a database, the CPU has been highUsing SQL statements such as the following, we look at the time the database waits, contention:Select S.sid, s.serial#, ' kill-9 ' | | p.spid, s.machine, s.osuser,

Comparison of two-live solutions: ASM vs V-plexWang WenjieOracle Company Principle System AnalystOracle Advanced ServicesThe evolution of Oracle Database Center disaster Recovery has evolved over the years from initial cold backup, to hot backup, to