Logical and Physical Operator Icons
If you want to better understand the graphical execution plans displayed in SSMS, it helps to be able to recognize what each of the displayed icons represents. Recognizing them is especially valuable when you need to quickly locate operations that appear out of place for the type of query being executed. The following sections cover the more common logical and physical operators displayed in the Query Analyzer execution plans.
Assert is used to verify a condition, such as referential integrity (RI) or check constraint, or to ensure that a scalar subquery returns only a single row. It acts as sort of ...