Partition ID of the data. When a MapR stream is divided into partitions, a sequential ID is assigned to each event and is unique to each event within the partition. Use the partition ID to identify the event that you want to consume from a particular partition.

Key value associated with an event. You can group events based on the key value and then process the data.

Time at which an event is generated. You can accumulate streamed data into data groups and then process the data groups based on the timestamp values.