Oozie is a system for describing the workflow of a job, where that job may contain a set of map reduce jobs, pig scripts, fs operations etc and supports fork and joining of the data flow.
It doesn't however allow you to stream the input of one MR job as the input to another - the map-reduce action in oozie still requires an output format of some type, typically a File based on, so your output from job 1 will still be serialized via HDFS, before being processed by job 2.
The oozie documentation has an example with multiple MR jobs, including a fork: