Post is a table that store records about posts and published torrent, information like info_hash and bencode are stored in corresponding row.
The idea behind this is that, any post must be accompanied by a related torrent file, of couse its info_hash and bencode will be stored together with the post for storage convenience.
Postgresql provides byte array type bytea, thus I could store the bencoded torrent file into a line.
The info_hash column is for searching by.
The rate field will be dynamically computed when evaluatinng.
An example post object in json format is shown as below: