Redis key names are unique by definition and are binary safe in Redis. Binary safe being an example such as
"Foo", 42, 3.1415, 0xffKeys names can also be up to 512MB in size.
SET: Set provides a way to sore a value for a given key name.
set user:100 paul
GET: GET allows a user to getan individual key
get user:100
There are two commands to gather a list of keys names, these are KEYS and
SCAN. They allow you to iterate over all keys in a Redis database or to get
all key matching a certain pattern.
The KEYS command always blocks entries iterated over all keys, if youre
database contains millions of keys it could block the database for a long time.
Therefore do not use in production.
On the other hand SCAN also blocks but only iterates over a handful of keys at
a time. Which then returns a slot reference where you're able to continue your
iteration.
| Set Expiration | Inspect Expiration | Remove Expiration |
|---|---|---|
| EXPIRE | PTTL | PERSIST |
| EXPIREAT | TTL | |
| PEXPIRE | ||
| PEXPIREAT |
Keys also have a very useful property, you can define an expiration time or time to live. Redis will keep the key in memory until space is required or is forced out. Expiration times can be set in milliseconds, seconds or a UNIX timestamp.
Names are unique within the logical database. They are binary strings that can represent any key name. They occupy a flat name space so you'll need to define a consistent naming convention in order to separate concerns and domain objects.
Keys can be arbitrary large up to 512 megabytes although this is not really recommended. The presence and absence of keys can be used to determine if a value is set or not. And finally Redis can manage the automatic expiration of keys through a TTL.