Generate Explain Plans

Generate Explain Plans

The explain plan displays the steps a database uses to execute an SQL statement. The results of the plan display the order a database uses to search/join tables, the types of access used (indexed search or full table scan), and the names of indexes used. If you are using cost-based optimization, this statement also determines the cost of executing the statement. You can use explain plans to help tune SQL to improve performance.

Toad automatically generates an estimated explain plan when you select the Explain Plan tab in the Results pane.

Tip: If you occasionally closed the Results pane, you can restore it by selecting Editor | Windows | Script Results.

For SQL Server and Oracle, the following explain plans are available: 

• Estimated plan—Plan that is generated by executing the RDBS execution plan commands. This plan does not execute the query.

• Actual plan—Plan that was used to execute the SQL.

  Note: For Oracle, the explain plan is retrieved from the V_$SQL_Plan view. You must have proper privileges for V_$SQLAREA and V_$SQL_PLAN to generate an actual explain plan.

To generate an estimated explain plan

• Click in the Editor toolbar.

To generate an actual explain plan

1. Click in the Editor toolbar.
2. Execute the statement and select the Explain Plan tab.

Related Topics

View Result Sets 

View Execution Log Messages 

Optimize Cross-Connection Queries