Indeed, as implicitely said by Jeremy, DSS does not use any Derby DB. If you see Derby-related files and log lines, they are probably due to Hive using Derby as its metastore.
Note that Hive falls back to Derby when it finds no proper metastore configuration, and this can cause slowdowns. I would check Hive installation, and especially the metastore configuration in this case.
Hope this helps,
Jean-Baptiste Rouquier