Use the Compare section of the workflow
assistant for query tuning to compare two access plan graphs.
Before you begin
- Generate the two access plan graphs that you want to compare.
- Optional: Set your preferences for the types of differences to
show and the colors to use for highlighting the differences. Select . In the Preferences window, expand and select Access
Plan Graph Compare.
About this task
By comparing access plan graphs, you can determine whether
changes that you made to an SQL statement improved the access plan
for that statement. The
Compare section lists
and highlights the differences.
Procedure
To compare two access plan graphs:
- In the Query Tuner Workflow Assistant open,
click the Compare tab.
On
the Compare Access Plan Graphs page, the analysis
results in the current instance of the workflow assistant are listed
together with the analysis results that are in any saved projects
in your workspace.
For example, suppose that your workspace
contains a project named Project1. In that project, you saved analysis
results for two different SQL statements. In the current instance
of the workflow assistant, you run advisors and tools on an SQL statement
twice. Then, you go to the Compare section.
On the Compare Access Plan Graphs page, you see
these two lists.
Table 1. The two lists that appear for this
example situationLeft side |
Right side |
 |
 |
- On the left side of the Compare Access Plan Graphs page,
select an analysis result for the comparison.
- On the right side, select the other analysis result for
the comparison.
- Click the Compare button at the
top of the page. A new page opens that lists the
differences. The page also shows the access plan graphs side by side,
with the differences highlighted in each graph.
Example
Suppose that you wanted to generate an access plan graph
for an SQL statement that you captured, tune that statement, and then
generate an access plan graph for the tuned statement, so that you
could compare the access plans.
- In the workflow assistant, generate an access plan graph for an
SQL statement. You can generate an access plan graph from the Run
All Single-Query Advisors and Analysis Tools page of the Invoke section
of the workflow assistant. Click the Select What to Run button
to generate the access plan graph, as well as recommendations from
the advisors and a formatted version of the SQL statement. The workflow
assistant saves the results internally as Current® Project_data_server/Query
Group 1/Query 1/Analysis Result 1.
- Tune the SQL statement, according to the recommendations and your
analysis of the formatted query and access plan graph.
- Generate another access plan graph for the statement. Again, click
the Select What to Run button on the Run
Single-Query Advisors and Analysis Tools page of the Invoke section.
The workflow assistant saves the results internally as Current Project_data_server/Query
Group 1/Query 1/Analysis Result 2.
- Click the Compare tab.
- For the left side of the comparison, select Current Project_data_server/Query
Group 1/Query 1/Analysis Result 1.
- For the right side of the comparison, select Current Project_data_server/Query
Group 1/Query 1/Analysis Result 2.
- Click the Compare button at the top of
the page.