related forum thread: https://groups.google.com/forum/#!topic/idempiere/BA2WiEAZn7o

steps to reproduce
1. Set up Storage Provider Method for System Client: Database
2. Set up Storage Provider Method for GardenWorld Client: Filesystem
3. Set up an alert1 for GardenWorld client - simple select (use client alert processor too)
4. restart the server run alert processor from idempiere monitor.

Result: when alert fire
1. Alert Processor creates record to AD_Note to GW Client - its OK
2. AD_Attachment is created to AD_Client_ID=0 and title field = zip - so generated file will be saved to database by using System client Provider.

This behaviour cause rapid database size growing (e.g. 10alerts with 1MB per day increase database about 10 MB in a day month 300 MB. (in case of 3 clients per installation about 10 alerts could be 1GB per month)

REMARK: Discover when tested - similar approach in case when scheduler run a report and sent it in pdf. in this case ad_attachment created in given client properly but storage provider setup for attachment is ignored (still saved to database not to FS)