Shade decides how many hours a day your pool deck is actually usable. Between roughly 11am and 3pm, an unshaded deck sits empty in most of the country. Adding shade is the single cheapest way to increase the time people spend outside.
Undersized bases are the number one cause of umbrella failure and the reason canopies end up in the water. Freestanding umbrellas need considerably more weight than table mounted ones, and cantilevers need the most of all. When in doubt, go heavier. An in ground mount removes the question entirely and is the cleanest permanent solution on a new or resurfaced deck.
Always close and secure umbrellas when wind picks up or when you leave for the day.