exists_sample.py

# executed by Python
%timeit if Product.objects.all(): print("valid")                                                                                                                                                                                                                    
4.19 ms ± 118 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)


# executed in the database
%timeit Product.objects.exists()                                                                                                                                                                                                                     
226 µs ± 4.73 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)