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SQL Optimizer for SAP ASE 3.9 - User Guide

Introduction Tutorials Preferences Editor Functions SQL Information and Functions Performance Monitor SQL Inspector SQL Collector for Monitor Server SQL Scanner Index Advisor SQL Optimizer
SQL Optimizer Overview Optimization Engine Common Coding Errors in SQL Statements What Function Should l Use to Retrieve the Run Time? Unsatisfactory Performance Results SQL Optimizer Functions SQL Editor Optimized SQL Activity Log
SQL Worksheet SQL Formatter Database Explorer Code Finder Object Extractor SQL Repository Index Impact Analyzer Index Usage Analyzer Configuration Analyzer Migration Analyzer Abstract Plan Manager User-Defined Temp Tables SQL History Legal Information

Migration Analyzer Functions

Migration Analyzer > Migration Analyzer Functions

Below is a list of available functions within the Migration Analyzer window.

Menu Description

Analysis & Right-click Menu

New Analysis/Abort Analysis

Right-click Menu

Add Folder

Right-click Menu

Add Scenario

Right-click Menu

Add SQL

Right-click Menu

Regenerate

Right-click Menu

Modify

Right-click Menu

Rename

Right-click Menu

Delete

Right-click Menu

Go To Undo Changes

Right-click Menu

Confirm Changes

View Menu

Last Migration Analysis Details

 

Related Topic

Abstract Plan Manager

Abstract Plan Manager Overview

Abstract Plan Manager > Abstract Plan Manager Overview

The Abstract Plan Manager provides a window for you to easily view, create, delete and modify your abstract plan groups.

In Adaptive Server version 15 and above, the abstract plan enables you to influence the optimization of a SQL statement without having to modify the SQL statement syntax. If you cannot change the source code that contains your SQL statement, you can use the abstract plan to force Adaptive Server to use a specific query plan for a SQL statement. This is particularly useful if you have third party applications where you do not have access to the source code.

Another use of the abstract plan is to protect the performance from changes to the database. When changes are made to a database, Adaptive Server may choose a different query plan for a SQL statement as a result of the changes. The abstract plans provide a means for system administrators and performance tuners to protect the overall performance of a SQL statement from these changes since the abstract plan will cause Adaptive Server to always choose the same query plan.

In the SQL Optimizer window, you can find alternate abstract plans in one of two ways while you are optimizing a SQL statement. First, you can optimize to find only the compatible alternative abstract plans. Second, you can optimize to find the semantically equivalent SQL statements with alternative query plans and then choose the ones with compatible alternative abstract plans.

 

Related Topics

Abstract Plan Compatibility with Original SQL

Abstract Plan Manager Window

Open the Abstract Plan Manager

Abstract Plan Group Functions

Export a Group to a Table

Import an Abstract Plan for each User

Abstract Plan ID Functions

Use Saved Abstract Plans

Abstract Plan Group

Abstract Plan Manager > Abstract Plan Group

Abstract plans are saved to an abstract plan group. The group has the following elements associated with it:

  • Database
  • User-ID
  • SQL statement
  • Abstract Plan

When you save an abstract plan, you specify the database, group and user. This means that you can have a different abstract plan for different users. It enables SQL optimization to be based on the user’s individual activities.

Here is an example of where you might want to have a different abstract plan for different users. In this example, the column emp_sex is indexed.

select * from employee where emp_sex=:var_sex

If 90% employees are male, then the SQL statement to retrieve the records where the employees are male should not be indexed for the best results.

But the SQL statement to retrieve the 10% of the employees who are female should be indexed.

For Group A users, who always select "male" employees, the Abstract Plan should do full table scan. For Group B users, who always select "female" employees, the Abstract Plan should use an index scan.

If you use the default group of ap_stdin, you can set Adaptive Server to use this group server-wide. You must save each abstract plan that you want to use system-wide in this group.

You can set up Adaptive Server to use different abstract plans for the same SQL statement from different applications. In this case, you create a different group for each application. For each user that you want to use a specific abstract plan, you must save that abstract plan in the group.

 

Related Topics

Abstract Plan Compatibility with Original SQL

Abstract Plan Manager Window

Open the Abstract Plan Manager

Abstract Plan Group Functions

Abstract Plan Manager Overview

Export a Group to a Table

Import an Abstract Plan for each User

Abstract Plan ID Functions

Use Saved Abstract Plans

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