SQL Optimizer for DB2 LUW 4.3.1

The Generate Indexes tab on the Options window allows users to define the optimization level and other settings used to generate index-set alternatives.

The Settings include:

Intelligence

Index Options

General

Intelligence

Closed View Generate Indexes tab – Intelligence button options

The Intelligence page under the Generate Indexes tab on the Options window allows you to select the optimization level for generating index-set alternatives.

Intelligence Level

Option	Description
Custom	Use the Index Options page settings to determine the optimization level as needed to generate the index-set alternatives.
Predefine	Set a specific optimization intelligence level here. Values on the Index Options page adjust to this level. Levels range from 0 to 10. The higher the setting, the higher the number of Index sets generated. Note: The General page settings can be adjusted independent of which intelligence level is chosen.

Option

Description

Custom

Use the Index Options page settings to determine the optimization level as needed to generate the index-set alternatives.

Predefine

Set a specific optimization intelligence level here. Values on the Index Options page adjust to this level. Levels range from 0 to 10. The higher the setting, the higher the number of Index sets generated.

Note: The General page settings can be adjusted independent of which intelligence level is chosen.

Index Options

Closed View Generate Indexes tab – Options button options

Index Options	Description
Retrieve index selectivity by sampling a maximum number of records (Default: 1000, Range = 10 to 99999)	Specify the number of records to be selected for determine the selectivity of the data.
Evaluate columns in SELECT list	Specify whether to consider SELECT list columns when generating indexes.
Maximum number of columns in a composite index (Default 4, Range 1 to 30)	Specify the maximum number of columns in a composite index.
Maximum number of indexes in an Index Set (Default 4, Range 1 to 99)	Specify the maximum number of indexes in an index set.

Index Generation Quotas	Description
Index Generation Quota	Specify the maximum number of indexes generated.
Index Set Generation Quota	Specify the maximum number of index sets generated.

SQL Scanner

Quest SQL Optimizer for IBM® DB2® LUWmaximizes SQL performance by automating the manual, time-intensive and uncertain process of ensuring that SQL statements are performing as fast as possible. SQL Optimizer analyzes, rewrites, and evaluates SQL statements within multiple database objects, files, or SQL statements captured by the DB2 Event Monitor. With SQL Optimizer, you can analyze and optimize all your problem SQL from multiple sources. SQL Optimizer also provides you a complete index optimization and plan change analysis solution, from index recommendations to simulated index impact analysis, through comparison of multiple SQL access plans.

SQL Optimizer provides you with the following main modules.

SQL Optimizer (including SQL Rewrite and Generate Indexes functions)

Index Impact Analyzer

Index Usage Analyzer