I am planning to make a pasta dish and would like to know if adding 1Tb spoon of olive oil while boiling 500 gram of pasta make it sticky. What are the other advantages and disadvantages of this approach?
Some people think adding olive oil to pasta water will keep the pasta from sticking, but in reality it does absolutely nothing. Adding a tablespoon of oil to pasta water won't affect the outcome in the slightest, doing that is a waste of a good ingredient.
Adding olive oil to pasta after it has been drained on the other hand will keep the pasta from sticking. It will also make it oily, which may not be what you want.
For most Italian pasta dishes, adding oil to cooking water is typically not recommended. The assumptions are (a) the oil floats on the surface and does little to impact the pasta, or (b) the oil coats the pasta making it more difficult for the condiment to adhere when it is combined with the pasta. The exception might be to add some oil to drained pasta that will be used for a pasta salad. This would keep the cooling noodles from sticking together.