Working with Multiple Databases
Problem
You want to keep different kinds of data — belonging to different applications, for example — separate from each other, but store them all in the same Redis instance.
Solution
Use different Redis databases for different kinds of data.
In Redis, databases are identified by an integer index, not by a database name.
By default, a client is connected to database 0.
With the SELECT command you can switch to a different database:
redis> select 3
OK
All subsequent commands will then use database 3, until you issue another SELECT.
Discussion
Each Redis database has its own keyspace. By using different databases for your 'staging' and 'production' data, for example, you don't have to worry about key clashes between the two.
There is also a command to drop all the data in a single database:
redis> flushdb
OK
This comes in very handy if you want to reset your 'staging' database.
If you want to get rid of all the data in a Redis instance, you can use
FLUSHALL instead. But be careful, there is no security check, and this
command is guaranteed to never fail.
The number of databases which is available can be configured in redis.conf —
by default, it is set to 16. Simply set it to a higher number if you need
more:
databases 42
Unfortunately, Redis does not provide a way to associate names with the different databases, so you will have to keep track of what data goes where yourself.