问社会网络的Cassandra数据建模

EN

- You wanted to query for posts by a certain user and with the    assumption that you would have a decent number of users. This would  distribute records evenly, and your queries would only be hitting a  partition at a time.

- You had a small number of users with a large number of posts, which      would allow your data to be evenly spread across the cluster. However    you run the risk of having to query across multiple partitions.

- You wanted to query for posts being followed by a certain follower.    The records would be distributed and you would minimize queries    across partitions

CREATE TABLE IF NOT EXISTS social_media.posts_by_user (
user_id uuid,
post_id uuid,
message_text text,
created_on timestamp,
deleted boolean,
user_full_name text,
PRIMARY KEY ((user_id, created_on))
);
CREATE TABLE IF NOT EXISTS social_media.user_timeline (
follower_id uuid,
post_id uuid,
user_id uuid,
location_name text,
user_full_name text,
created_on timestamp,
PRIMARY KEY ((user_id, created_on))
);
CREATE TABLE IF NOT EXISTS social_media.post_counts (
likes_count counter,
view_count counter,
comments_count counter,
post_id uuid,
PRIMARY KEY (post_id)
);