oracle performance tuning guide

introduced in Oracle7.0.1.2, with roughly 100 waiting events. This number is increased to approximately 150 in Oracle 8.0, with approximately 200 events in oracle8i and approximately 360 waiting events in oracle9i. There are two main categories of wait events, idle (idle) Wait events and non-idle (non-idle) wait events.Information about idle events and non-idle events is now available through Google and can be found in much more detail, whileThere is

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that can be recovered. If you do not have a COMMIT transaction, Oracle restores the data to the state it was before it was deleted (exactly before the delete command was executed) and when the truncate is applied, the rollback segment no longer holds any recoverable information. When the command runs, The data cannot be restored. So very few resources are invoked and execution times are short. (Translator Press: truncate only in Delete full table app

$02HISTORYALARM20140801USABLEIDX_HISTORYALARM$02HISTORYALARM20140802USABLEIDX_HISTORYALARM$02HISTORYALARM20140803USABLEIDX_HISTORYALARM$02HISTORYALARM20140804USABLEIDX_HISTORYALARM$02HISTORYALARM20140805USABLE...... You can see that the index of the partition HISTORYALARM20140731 has been marked as UNUSABLE.When an index is marked as unavailable, the optimizer ignores these indexes, and Oracle does not maintain these indexes when changing the table in

The Oracle tutorial you are looking at is: Oracle SQL Performance Tuning Series Learning Ii. 4. Select the most efficient table name order (valid only in the Rule-based optimizer) The Oracle parser processes the table names in the FROM clause in Right-to-left order, so the

The Oracle tutorial being looked at is: Oracle SQL Performance Tuning series learning one. 1. Choose the appropriate Oracle OptimizerThere are 3 Oracle optimizer types:A. Rule (rule-based) b. Cost (based on costs) c. CHOOSE (optio

Tags: style blog http color using OS IO strongOne, automatic workload library (Automatic Workload Repository,awr)The Automated Workload library (Automatic Workload repository,awr) is a tool provided by Oracle Corporation. AWR can automatically collect, process, and save performance statistics, which are stored in memory and then saved in a database that can be displayed in a report or queried through a view

------------------------------------------------------------------------------------------Idx_ historyalarm$02historyalarm20140731unusableidx_historyalarm$02historyalarm20140801usableidx_historyalarm$ 02historyalarm20140802usableidx_historyalarm$02historyalarm20140803usableidx_historyalarm$ 02historyalarm20140804usableidx_historyalarm$02historyalarm20140805usable ...You can see that the index of the partition HISTORYALARM20140731 is already labeled unusable.When indexes are marked as unavailable

processes are running (in the Solaris 8 operating environment is prstat ). In addition, many commercial and unsupported products can be used for performance monitoring. SE Toolkit is a free and unsupported product. For more information about different versions of SE Toolkit, see Sun Performance SE Toolkit page ). SE Toolkit reports disk activity, CPU utilization, TCP and network connections, memory, and mo

information on the use and performance of the main hardware components of the system, as well as the performance of the operating system itself. This information is critical for detecting potential resource consumption, such as CPU cycles and physical memory, as well as detecting poor performance of peripherals such as disk drives. Operating system statistics ar

For some current releases, three dynamic performance views are available for DBAs (Database Administrator, Database Administrator) and developers, namely V $ SQL, V $ SQLAREA, and V $ SQLTEXT.These views can be used to collect statistics about SQL command execution. In Oracle 10g and Release 2, the fourth dynamic performance view, V $ SQLSTATS, is added to facili

details of the table, according to the name of the detail table can generally understand its content, and feel that there is no need to thoroughly understand the details of the structure of the table. and different versions of Oracle have a corresponding change to the structure of these tables. All, here the structure of the table and the corresponding contents are omitted ... For example: You see Stats$sql_summary, you can certainly think of a SQ