This will make SQL*Plus display the execution plan for the query you are running.Įxplain Plan and Autotrace buttons in SQL Developer Explain Plan vs. If you are using SQL*Plus, you can set the AUTOTRACE system variable to ON or TRACEONLY, like this: The method used to display an execution plan and the way it will be displayed may vary depending on the tool you are using.
In an execution plan, you can see the list of steps the database will have to perform to execute the statement, along with the cost associated with each step, which is very useful because you can see which of the steps are using more resources, and thus, probably taking more time to complete. You can think of an execution plan as the combination of steps used by the database to execute an SQL statement. In this article, I cover the basics of execution plans, with the goal of helping people new to SQL tuning understand what they are and how they can be used as part of an SQL tuning process. One of the most basic tasks you need to perform when tuning SQL statements is determining the causes of the performance problem, and to do that, you will most likely need to analyze the execution plan of the problematic statement.
0 kommentar(er)
