Let one Operator finished the job before another one begin in Hyracks

[mingda li]

Hi,

Now,I am trying to build a Bloom Filter(BF) before join. The BF is build in
each node and sent to one node to combine. I want to set a stop sign there
before sending the BF in each node. The stop sign means it can only send
the BF after it is build.
The class HyracksConnection.waitForCompletion may help this. But I am not
sure how to use it.
Should I build two jobs: hcc.waitForCompletion(jobBuildBF);
jobidSendBF=hcc.startJob(); ?
Has anyone ever used the HyracksConnection.waitForCompletion?

Thanks,
Mingda