The <var> element is a child of the plan <varList> element and is used to declare a plan variable including name and value.
This element has the following attributes:
name – A required attribute of type identifier, which is the name of the local variable. The name must be unique among every variable in the containing <varList>. Variables associated with the top-level <executionPlan> must also be unique among the plan parameters.
default – A required attribute that is a string that is the default value of the plan variable. This value can include references to other plan variables that have been declared earlier, to session variables, and to plan parameters. If this plan is a simple plan, you can include references to target host attributes and to installed component variables.