In accordance with an embodiment, described herein is a system and method for providing sandboxing support in a multidimensional database environment. A plurality of sandboxes and a baseline data can be provided in a multidimensional database server, with each sandbox created for a particular “what-if” analysis, and configured to store one or more changes to the baseline data. When a request is received for a report on a particular “what-if” analysis from a client/user, the multidimensional database server can split the request into a first query and the second query, with the first query directed to a sandbox associated with the client/user, and the second query directed to the baseline data. The multidimensional database server can merge results from the first query and the second query, and perform aggregations and calculations on the merged data, before sending the merged data to a client.