Use the Preferences window to set default values for settings
that determine how Visual Explain operates and how it displays diagrams.
Procedure
To set preferences for Visual Explain:
- Select Window > Preferences.
- In the tree view of the Preferences window,
select Data > Visual Explain.
- On the Visual Explain page, set the
following options:
- Specify whether to launch the Visual Explain wizard
when you right-click an SQL statement, view, stored procedure, or
user-defined function and select Visual Explain. The wizard allows you to override preferences. If you clear
this option, Visual Explain uses the preferences.
- If your project is associated with a DB2® data server, specify whether Visual Explain
saves in the explain tables the explain data that it collects for
the statement.
- If your project is associated with an Oracle data server,
specify the plan_table name to be used and the optimizer mode.
- On the Query Explain Settings page,
specify default values for special registers. Changing
these values modifies how Visual Explain gathers explain data to use
when generating the access plan diagram.
Attention: Please
be aware of the following information regarding DB2 data servers.
- For DB2 for z/OS®: If you specify different values for
CURRENT SCHEMA and CURRENT SQLID, Visual Explain searches for explain
tables that are qualified by the value of CURRENT SQLID. If Visual
Explain does not find explain tables that are qualified by the value
of CURRENT SQLID, Visual Explain attempts to create the explain tables
under that value.
- For DB2 for Linux®, UNIX®,
and Windows®: If you
change the value of CURRENT SCHEMA to a value that contains special
characters, you must delimit the value with single quotation marks.
- For DB2 for Linux, UNIX,
and Windows: Select
the Collect column and column group statistics check
box if you want Visual Explain to collect detailed statistics about
clustered columns and columns that participate in a GROUP BY clause.
- On the Viewer page, change various
behaviors and colors of diagrams.
- On the Nodes page, change the default
appearance of nodes. You can change the text, color, and
shape of the different types of nodes. You can also choose whether
to highlight selected nodes, shadow nodes, or show information about
nodes when you move your mouse cursor over them.