Difference between Redis GET/SET and hash tables

Question

I'm new to Redis and databases in general. I'm confused about when I should use the GET/SET commands and when I should create a hash table and use the HGET/HSET commands.

Let's say I want to keep track of the prices of various products in a shop.

Using GET and SET:

SET pencil 3
SET eraser 4
SET calculator 60

GET pencil
GET eraser
GET calculator

Using HGET and HSET:

HSET mystore pencil 3
HSET mystore eraser 4
HSET mystore calculator 60

HGET mystore pencil
HGET mystore eraser
HGET mystore calculator

For this shop example, which method is preferred? What's the difference between using the GET/SET commands and using the HGET/HSET commands? What are some of their use cases?

Thanks

Answer 1

Hashes are used to store objects in Redis and GET/SET are used to store a single string (or int).

From your description, in your case there is nothing different with HSET and GET/SET. If your Redis database is used only for mystore object (or something similar), you can just use GET/SET with the key.

And if there are multiple similar mystore objects, I recommend to convert to hash since it will be much easier to organize the key-values.

For performance, key-value string and hash are both implemented using dict (hash will use ziplist if data set is small). So it will always be O(1) time complexity.