text: INSERT INTO animals (name) VALUES ('Agumon'), ('Gabumon'), ('Pikachu'), ('Devimon'), ('Charmander'), ('Plantmon'), ('Squirtle'), ('Angemon'), ('Boarmon'), ('Blossom');
  
  INSERT INTO vets (name) VALUES ('William Tatcher'), ('Maisy Smith'), ('Stephanie Mendez'), ('Jack Harkness');
  
  -- Add an email column to your owners table
  ALTER TABLE owners ADD COLUMN email VARCHAR(120);
  
  -- This will add 3.594.280 visits considering you have 10 animals, 4 vets, and it will use around ~87.000 timestamps (~4min approx.)
  INSERT INTO visits (animal_id, vet_id, date_of_visit) SELECT * FROM (SELECT id FROM animals) animal_ids, (SELECT id FROM vets) vets_ids, generate_series('1980-01-01'::timestamp, '2021-01-01', '4 hours') visit_timestamp;
  
  -- This will add 2.500.000 owners with full_name = 'Owner <X>' and email = 'owner_<X>@email.com' (~2min approx.)
  insert into owners (full_name, email) select 'Owner ' || generate_series(1,2500000), 'owner_' || generate_series(1,2500000) || '@mail.com';