Wash the cucumber and grate it using the large holes of a box grater. Use a cheesecloth, fine mesh bag, or clean kitchen towel to squeeze out as much liquid as possible from the grated cucumber.

In a bowl, combine the yogurt, olive oil, and vinegar. Mix well.

Crush the garlic and add a pinch of salt. Add the cucumber and garlic to the bowl with the yogurt and mix thoroughly. Chill in the refrigerator before serving.