oracle performance tuning guide

of disk sorting will be greatly increased. This is mainly because at the end of the month, users will make statistics on the transaction data for the month. So at the beginning of the month, because of the number of transactions, so there will be more disk sorting occurs. In this case, it is necessary for the database administrator to adjust the relevant parameters. However, this adjustment is a temporary adjustment, until the cycle has passed, still need to transfer the parameters back. Only i

Summary: This article begins with a detailed introduction to the concept of shared pool in Oracle and the memory structure included. It then provides an in-depth overview of Oracle's management mechanisms for shared pool. Finally, the paper introduces the practical method of buffer cache monitoring and tuning. 1. The concept of shared pool Oracle databases, as

filtering out unwanted records before group by. The following two queries return the same result but the second one is significantly faster.The code is as follows:Low efficiency:SELECT JOB, AVG (SAL)From EMP GROUP job has job = ' president ' and AVG (SAL) >xxxEfficient:SELECT JOB, AVG (SAL)From EMPWHERE JOB = ' President 'OR job = ' MANAGER ' GROUP JOB having and AVG (SAL) >xxx7, usually, if the statement can avoid the use of subqueries, as far as possible without sub-query.Because the overhead

. Create_snapshot; We can also use the Dbms_workload_repository package to complete the baseline, the default settings and other operations.ADDM (Automatic Database diagnostic Monitor AWR)Oracle is an internal consulting system, can automatically complete the most database of some optimization recommendations, giveSQLThe optimization, the creation of the index, the collection of statistics and other suggestions.ADDM report Generation:Sqlplus>@?/rdbms/

Absrtact: By discussing and studying the characteristics and principles of Oracle Server and Client/server, this paper expounds some principles and methods of improving and adjusting the performance of Oracle Application system. Keywords: Oracle; client/server; system whole zone; network I/O; rollback segment.

so that you can mark the snapshot information set at important times. A baseline is defined between a pair of snapshots, and the snapshot is identified by their snapshot sequence number. eachThe baseline has only a couple of snapshots. A typical performance tuning practice starts with collecting baseline collections of metrics, making changes, and then capturing another set of baselines. You can compare th

the deterioration of performance is a variety of factors, and sometimes the results of the performance degradation caused by multiple elements, this requires the database administrator has a more comprehensive computer knowledge, can be sensitive to the impact of the database performance of the main reason. In addition, good database management tools are also im

As mentioned in parts 1th and 2nd, there are several relatively easy steps to improve performance you can take, one of these steps involves using an automated tool to "guide" you to write SQL statements, there are many production performance analysis or performance tuning to

Io is very relevant, when the free buffer waiting in the v$session_wait of the entry is very small or not, Explain the DBWR process of your system will be enough, do not need to adjust, there are many items of free buffer wait, your system must feel very slow, then your DBWR is not enough, the resulting wio has become your database performance bottlenecks, the solution is as follows: A.1 to increase the write process while adjusting the db_block_lru_

Label:The story of Ash and awr 1.1 About Ash As we all know, when a user performs an operation in an Oracle database, it is necessary to create the appropriate connection and session, where all current session information is saved in the dynamic performance view v$session, where the DBA can see what the user is actually doing, or the current wait event. This part of the information is usually the key inform

oracle| Data | database | Performance Oracle is a high-performance database software. The user can adjust the parameters to achieve the optimization of performance. Performance optimization is mainly divided into two parts: first,