On a workflow with 1001 subworkflows, pegasus-statistics fails with:

File "/home/rynge/Pegasus/install/trunk.2012-06-11-202745/lib/pegasus/externals/python/sqlalchemy/engine/default.py", line 335, in do_execute
cursor.execute(statement, parameters)
sqlalchemy.exc.OperationalError: (OperationalError) too many SQL variables u'SELECT CAST(sum(invocation.remote_duration * job_instance.multiplier_factor) AS FLOAT) AS anon_1 \nFROM invocation, job_instance \nWHERE invocation.task_submit_seq >= ? AND invocation.job_instance_id = job_instance.job_instance_id AND invocation.wf_id IN (?, ?,
...

A submit directory for such a workflow can be found at: http://pegasus.isi.edu/static/jira-related/galactic-plane-20120613-085617.tar.gz