What are all the possible breed type and size type combinations?
SELECT DISTINCT breed_code ,  size_code FROM dogs
SELECT DISTINCT breed_code ,  size_code FROM dogs
[{'breed_code': 'ESK', 'size_code': 'LGE'}, {'breed_code': 'BUL', 'size_code': 'LGE'}, {'breed_code': 'BUL', 'size_code': 'MED'}, {'breed_code': 'HUS', 'size_code': 'MED'}, {'breed_code': 'ESK', 'size_code': 'SML'}, {'breed_code': 'HUS', 'size_code': 'SML'}, {'breed_code': 'ESK', 'size_code': 'MED'}]