datasets generate large arrow file
{'login': 'osayes', 'id': 18533904, 'node_id': 'MDQ6VXNlcjE4NTMzOTA0', 'avatar_url': 'https://avatars.githubusercontent.com/u/18533904?v=4', 'gravatar_id': '', 'url': 'https://api.github.com/users/osayes', 'html_url': 'https://github.com/osayes', 'followers_url': 'https://api.github.com/users/osayes/followers', 'following_url': 'https://api.github.com/users/osayes/following{/other_user}', 'gists_url': 'https://api.github.com/users/osayes/gists{/gist_id}', 'starred_url': 'https://api.github.com/users/osayes/starred{/owner}{/repo}', 'subscriptions_url': 'https://api.github.com/users/osayes/subscriptions', 'organizations_url': 'https://api.github.com/users/osayes/orgs', 'repos_url': 'https://api.github.com/users/osayes/repos', 'events_url': 'https://api.github.com/users/osayes/events{/privacy}', 'received_events_url': 'https://api.github.com/users/osayes/received_events', 'type': 'User', 'site_admin': False}
[{'id': 1935892857, 'node_id': 'MDU6TGFiZWwxOTM1ODkyODU3', 'url': 'https://api.github.com/repos/huggingface/datasets/labels/bug', 'name': 'bug', 'color': 'd73a4a', 'default': True, 'description': "Something isn't working"}]
[]
Hi ! The cache files are the results of all the transforms you applied to the dataset using `map` for example.
Did you run a transform that could potentially blow up the size of the dataset ? @lhoestq,
I don't remember, but I can't imagine what kind of transform may generate data that grow over 200 times in size. 
I think maybe it doesn' matter, it's just cache after all.
Checking the large file in disk, and found the large cache file in the cifar10 data directory:

![image](https://user-images.githubusercontent.com/18533904/186830449-ba96cdeb-0fe8-4543-994d-2abe7145933f.png)

As we know, the size of cifar10 dataset is ~130MB, but the cache file has almost 30GB size, there may be some problems here.
{'url': 'https://api.github.com/repos/huggingface/datasets/issues/4897/reactions', 'total_count': 0, '+1': 0, '-1': 0, 'laugh': 0, 'hooray': 0, 'confused': 0, 'heart': 0, 'rocket': 0, 'eyes': 0}