SQL Optimizer for SAP ASE 3.8

Adaptive Server generates an abstract plan based on the SQL syntax itself. If a SQL statement is transformed to another syntax that the Adaptive Server optimizer cannot transform internally, then the abstract plans are not compatible. Therefore, even though two SQL statements may be semantically equivalent, their abstract plans are not compatible.

For example, take this SQL statement as your original SQL statement:

SELECT A CITY FROM A, B, C

WHERE A.CITY =B.CITY

AND B.CITY=C.CITY

And take this semantically equivalent alternative SQL:

SELECT A.CITY FROM A, B, C

WHERE A.CITY =B.CITY

AND B.CITY=C.CITY

AND A.CITY=C.CITY

The transforms adds the new condition, A.CITY=C.CITY, and if the Adaptive Server optimizer cannot generate A.CITY=C.CITY internally for your original SQL, then an index scan from A.CITY to C.CITY or from C.CITY to A.CITY is not possible for your original SQL. So, the new abstract plan is not compatible for the original SQL.

Also, if an OR condition is transformed to a UNION, the new abstract plan is so different from the original SQL that there is no way for the original SQL to be compatible with the new abstract plan.

Related Topics

Abstract Plan Manager Overview

Abstract Plan Group

Why Save the Abstract Plan?

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 Manager Window

Abstract Plan Manager > Abstract Plan Manager Window

View Abstract Plan Manager Window

Left Pane

The left pane is a tree structure for the managing of the elements of the abstract plan: Groups, Users, and Plan IDs.

Right-click any element to bring up the right-click menu with the functionality for that element.

Right Pane

The right pane displays the information that corresponds to the group, users, or plan ID that is selected in the left pane.

Related Topics

Abstract Plan Manager Overview

Abstract Plan Group

Why Save the Abstract Plan?

Abstract Plan Compatibility with Original SQL

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

Open the Abstract Plan Manager

Abstract Plan Manager > Open the Abstract Plan Manager

To open the Abstract Plan Manager

Click ..

Related Topics

Abstract Plan Manager Overview

Abstract Plan Group

Why Save the Abstract Plan?

Abstract Plan Compatibility with Original SQL

Abstract Plan Manager Window

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 Functions

Abstract Plan Manager > Abstract Plan Group Functions

The following are the functions that are performed on abstract plan groups.

To use these functions

Right-click the group name in the left pane and select one of the following functions.

Item	Description
Create	Creates a new abstract plan group
Drop	Drops the select abstract plan group.
Purge	Deletes all abstract plans in the selected group
Copy All Plan	Copies all abstract plans in the selected group to another group.
Rename	Renames the abstract plan group.
Export	Exports the abstract plan group to a table.
Import	Imports an exported table to a database, user and group
Compare	Compares the differences between two groups.