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SQL Optimizer for SAP ASE 3.8 - Installation Guide

Index Advisor Window

The Index Advisor window is divided into the following sections:  

Top Pane

SQL Editor tab

Used to enter the SQL statement you wish to analyze for index recommendations.

Database Objects tab

Displays information about the tables used in the SQL statement.

Left Bottom Pane

Displays the table names accessed by the SQL Statement

Right Bottom Pane

Displays specific information about the selected table on different tabs: Definition, Columns, Indexes, Constraints/Keys, and Data.

Index List tab

Displays a list of the individual index candidates proposed by the Index Advisor. These are the indexes used in the Index alternatives displayed in the bottom left pane. The following information displays on this page:

Item

Description

Database

Database where index resides

Owner

Owner of the index

Table

Indexed table

Columns

Indexed column(s)

Index

Index name. All indexes generated by SQL Optimizer will be prefixed with QUEST_SX_IDX_.

Selectivity

Selectivity value. The selectivity is the percentage of rows in the table that the SQL statement selects. A SQL statement that selects a small percentage of the rows from a table has good selectivity, while a query that selects a large percentage of rows has poor selectivity. The maximum selectivity value is 1 and it corresponds to the best selectivity.

Note: A Sample Block of the actual table data is used to calculate the selectivity value therefore it is possible that the value may vary according to what Sample Block is used.

Context

Index DDL for creating the index.

Time tab

Displays the run time information for the SQL statement using the alternative indexes. The values are filled in after the Show Plan, Batch Run, Run for First Record, or Run for All Records functions are executed.

Statistics tab

Displays the run time statistics for the SQL statement using the alternative indexes. These values are filled in after the Batch Run, the Run for First Record, or Run for All Record functions are executed. An image\I_RedX.gif is placed in the far left column if for some reason the index is not created when the SQL statement is executed.

Chart tab

Charts the run time statistics for the SQL statement using the alternative indexes.

Bottom Left Pane

Displays the Used Index which is the index(es) that are currently used by the SQL statement, the Index candidates which are generated by the Index Advisor, or the Index Sets that are created using the User-Defined Index window.

Bottom Right Pane - SQL Information Pane

Displays information about the SQL statement when it is using a specific index.

 

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