What's the practical difference between keeping data in multiple hashes (<code>HSET foo oof 1</code>, <code>HSET bar rab 2</code>) and using plain keys in a hierarchy (<code>SET foo:oof 1</code>, <code>SET bar:rab 2</code>)?

According to the manual, you'd use hashes to represent a single object. Also, it's not that efficient to iterate over Redis keys, so if you need to get all the data from a single object, <code>HGETALL</code> is your friend, not a <code>KEYS thing:10:*</code>/multiget fiasco. However, you can't e.g. set expiry for only one key of a hash, so if you need that functionality, you'll want to use regular keys.

Redis hash vs key hierarchy

1 Answers

According to the manual, you'd use hashes to represent a single object.

Also, it's not that efficient to iterate over Redis keys, so if you need to get all the data from a single object, HGETALL is your friend, not a KEYS thing:10:*/multiget fiasco.

However, you can't e.g. set expiry for only one key of a hash, so if you need that functionality, you'll want to use regular keys.