Transactions: If I mutate a field of a node, will only the field get locked, or the whole node?

Thanks a lot!! I thought that there might be complications because the relationships are inversive, so that basically means dgraph would write under the hood 19000 edges to that single specific node

type Hashtag {
    ...
    posts: [Post] @hasInverse(field: hashtags)
}
type Post {
    ...
    hashtags: [Hashtag] @hasInverse(field: posts)
}

/// yes correct I mean 19000 different connections concurrently

so there won’t be any problems?