Saving the abstract plan for a SQL statement preserves how the SQL statement is executed. Therefore, when changes occur in the database environment, the query plan used to execute the SQL statement remains constant.
One major advantage of saving the abstract plan is that you can optimize the SQL statement without altering the SQL text. This is an ideal solution for when you do not have the source code from a vendor but want to improve the performance of the database application. The saving of the abstract plan can be very useful when you are considering making changes to the configuration parameters or you are migrating to another version of Adaptive Server and you want to preserve the current performance of SQL statements that are critical to the performance of your applications.
These database environment changes may include:
Parallel degree
Table partitioning
Indexing
Database software upgrades
Changes in data columns
You can save an abstract plan from the following modules:
To save in... | See: |
SQL Optimizer |
Save Abstract Plan |
SQL Scanner |
Save Abstract Plan. |
Index Impact Analyzer |
Right Pane for SQL Statements |
Configuration Analyzer |
Right Pane for SQL Statement |
Migration Analyzer |
Right Pane for SQL Statement |
SQL Repository |
SQL Repository Window |
Abstract Plan Compatibility with Original SQL
Open the Abstract Plan Manager
Import an Abstract Plan for each User
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.
Open the Abstract Plan Manager
Import an Abstract Plan for each User
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.
The right pane displays the information that corresponds to the group, users, or plan ID that is selected in the left pane.
Abstract Plan Compatibility with Original SQL
Open the Abstract Plan Manager
Import an Abstract Plan for each User
To open the Abstract Plan Manager
Click ..
Abstract Plan Compatibility with Original SQL
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