Atm, key is not a reserved key word in ksqlDB. Thus users could use it as a name for streams/tables/columns etc. We should add key as a reserved key word though to make sure we can use it if we evolve the language further.

Basically, we don't need to have kafka-console-consumer, we have mill instead: https://github.com/ThreeDotsLabs/watermill/tree/master/tools/mill

It would be nice to replace it in all examples.

It can be very difficult to piece together a reasonably estimate of a history of events from the current workers logs because none of them have timestamps.

So for that end, I think we should add timestamps to the logs.

This has some cons:

1. We can't just use @printf like we have been until now. We need to either include a timestamp in every @printf call (laborious and error prone) or c

For example, given a simple pipeline such as:

Pipeline p = Pipeline.create();
p.readFrom(TestSources.items("the", "quick", "brown", "fox"))
 .aggregate(aggregator)
 .writeTo(Sinks.logger());

I'd like aggregator to be something requiring a non-serialisable dependency to do its work.

I know I can do this:

Pipeline p = Pipeline.create();
p.readFrom(TestSource