O notation(An indication of the relative performance of an algorithm. An algorithm or the method that implements it is said to be O if its execution is a constant, O(log n) if its execution is proportional to the natural log of n, or O(n) if its execution is proportional to n. O notation is frequently used as a way to compare the relative performance of operations on collections, in which case n is usually the number of elements in the collection; An indication of the relative performance of an algorithm. An algorithm or the method that implements it is said to be O(1) if its execution is a constant, O(log n) if its execution is proportional to the natural log of n, or O(n) if its execution is proportional to n. O notation is frequently used as a way to compare the relative performance of operations on collections, in which case n is usually the number of elements in the collection)
Crow's Foot(A specification language for describing data structures. You can use the Crow's Foot entity and relationship shapes to diagram the structure of databases)