I was asked recently about permissions of uploaded data in OBIEE and Data Visualization. (New) in version 126.96.36.199 I am able control who gets to see the data I upload via the Permissions tab of the Data Sources dialog box. I can control via individual Users (good for quick collaboration between users) or via Roles (good for controlling access for corporate and departmental initiatives). See the below screenshot.
Here I prodney has granted permission to abell to access the Accounts data set. Similiarly, you can control who has access to the data that you upload. This has huge implications on how OBIEE users share data across an organization. As more and more users use the data mashup capabilties (including the new ones I shared in my webcast on new OBIEE 188.8.131.52 features), it will become more important how users control access to spreadsheets and raw tables in Oracle (and other) data sources. Let me know what best practices you are developing with this capability.