Objectives

After completing this lesson,you should be able to do the following:

Control optimizer options
Use optimizer hints
Employe plan stability
Use store outlines(在10g,11g已经过时)
Use SQL Trace and TKPROF

Overview

The purpose of this lesson is:

To provide mthods to determine the resources used by SQL statements:
- -Oracle Enterprise Manager
- -Statuspack
- -Explain plan
- -SQL Trace and TKPROF
- -Autotrace
To determine which SQL statements possibly require tuning
Not to tune the actual SQL statements

Optimizer Modes

There are two types of optimizer modes:

Rule-based:(Rule based Optimizer 俗称RBO)
- Uses a ranking system
- Syntax-and data dictionary-driven(基于语法逻辑和一些数据字典信息进行驱动的优化)
Cost-based:(Cost based Optimizer 俗称CBO)
- Chooses the path with lowest cost
- Statistics-driven(基于分析统计报表数据，进行优化驱动)

备注：目前RBO已经退出历史舞台，不在实际应用中使用;

转载于:https://www.cnblogs.com/arcer/archive/2013/05/04/3059267.html

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[bbk2228] 第41集 - Chapter 11-SQL Statement Tuning(00)

Objectives

Overview

Optimizer Modes

[bbk2228] 第41集 - Chapter 11-SQL Statement Tuning(00)相关推荐

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