Redis is a key-value store. 6 data types, 160 commands. Simple, fast, lightweight.
Redis makes you think. It's a database copnstruction kit.
No referentional integrity, no foreign keys.
Lots of duplication, no normalisation
Redis is ACID, because it is single-threaded: atomic. consistent, isolated.
It has transactions (but without rollbacks)
Indexes have to be built, using sets and zsets, they are not maintained automatically.
Redis is great for counting.
Widely used as a cache. Good for ephemeral storage, e.g. a shopping cart
CREATE TABLE redis (
k VARCHAR(512MB) NOT NULL,
v VARCHAR(512MB),
PRIMARY KEY (k)
)
Strings, integers, floats, bits, hash, sets, zsets