SELECT

Select the Valkey logical database having the specified zero-based numeric index. New connections always use the database 0.

By default, Valkey provides 16 logical databases, indexed from 0 to 15. You can increase this number by setting the databases parameter in the configuration file. This change must be made at startup and cannot be modified at runtime.

Selectable Valkey databases are a form of namespacing: all databases are still persisted in the same RDB / AOF file. However different databases can have keys with the same name, and commands like FLUSHDB, SWAPDB or RANDOMKEY work on specific databases.

In practical terms, Valkey databases should be used to separate different keys belonging to the same application (if needed), and not to use a single Valkey instance for multiple unrelated applications.

Valkey 9.0 and later supports multiple databases in cluster mode. You can use SELECT <dbid> to switch between them.

Since the currently selected database is a property of the connection, clients should track the currently selected database and re-select it on reconnection.

While there is no dedicated command to query the currently selected database for a connection, you can infer it from the output of CLIENT LIST or CLIENT INFO, where each client entry includes the db=N field indicating the selected database.

RESP2/RESP3 Reply

Simple string reply: OK.