[galaxy-dev] Purging datasets as part of workflow?

Hi, Is there an automatic way to permanently delete and purge datasets that are the result of intermittent tools in a workflow? That is, how can one automatically keep only the first and the last steps of an workflow without having to manually delete all the intermittent datasets and running the purge scripts? Thanks, Sveinung Gundersen -- Sveinung Gundersen, PhD. Head engineer, ELIXIR.NO / The Genomic HyperBrowser team Department of Informatics, University of Oslo, Boks 1072 Blindern, NO-0316 OSLO, Norway Email: sveinung.gundersen@medisin.uio.no. Phone: +47 93 00 94 54