The Redis DUMP command serialises the value stored at a specified key in a Redis-specific format and returns it to the user.
The serialisation format contains a 64-bit checksum that is used to make sure errors will be detected. The values are in the same format used by the RDB. Also, an RDB version is encoded inside the serialised value, so that different Redis versions with incompatible RDB formats will refuse to process the serialised value.
Continue readingThe Redis TOUCH command alters the last access time of a key or keys. It allows us to alter the access time of a key without accessing it directly.
In Redis, the EXISTS command checks whether the specified keys exist. It returns an integer reply with the number of keys that exist.
We can use the command to check for the existence of one key or multiple keys.
Continue readingThe Redis SORT_RO command is a read-only variant of the SORT command. It allows us to sort lists, sets, and sorted sets.
The SORT command enables us to have the sorted elements returned to the client, or stored in a separate key. But the SORT_RO command only allows us to have them returned to the client.
The SORT_RO variant was introduced in Redis 7.0.0 to enable SORT functionality in read-only replicas without breaking compatibility on command flags.
In Redis, the SORT command allows us to sort lists, sets, and sorted sets.
We can have the sorted elements returned to the client, or we can store them in a separate key.
Continue readingIn Redis, the TYPE command returns a key’s type. More specifically, it returns the string representation of the type of the value stored at a given key.
In Redis, the UNLINK command removes the specified keys. It’s similar to the DEL command, except that it performs the memory reclaiming in a different thread, so it is not blocking. The DEL command, on the other hand, doesn’t do this.
More specifically, the UNLINK command unlinks the keys from the keyspace, and then removes it later asynchronously.
In Redis, the RENAMENX command renames a key, but only if the new key doesn’t already exist.
RENAMENX is similar to the RENAME command, except that it only renames the key if the new one doesn’t already exist. The RENAME command on the other hand, will overwrite the new key if it already exists.
The Redis CLI allows us to easily run a command multiple times. All we need to do is prefix the command with the number of times we want it to run.
Continue readingIn Redis, the RENAME command renames a key. It allows us to give a key a new name.