Two new built-in functions `sparkplug_decode` and `sparkplug_encode` have been added to the rule engine SQL like language. These functions are used to decode and encode Sparkplug B messages. The functions are used as follows:

Decode a Sparkplug B message:

```sql
select
  sparkplug_decode(payload) as decoded
from t

```

Encode a Sparkplug B message:

```sql
select
  sparkplug_encode(json_decode(payload)) as encoded
from t
```

One can also specify a Sparkplug B message type by specifying it as the second argument to the `sparkplug_decode` and `sparkplug_encode` functions. The default is `Payload`:

```sql
select
  sparkplug_encode(sparkplug_decode(payload, 'Payload'), 'Payload') as encoded
from t
```