In some embodiments, a computer-implemented method for tuning queries for a multi-tenant database system is provided. A processor retrieves actual statistics associated with data stored on one or more servers in the multi-tenant database system. The data may be associated with one or more tenants of the multi-tenant database system. A subset of the actual statistics is selected, wherein the subset of the actual statistics is related to tenants having a data trait targeted for optimization. The processor determines synthetic statistics based on the subset of the actual statistics. An original query is received at the multi-tenant database system, wherein the original query operates upon data associated with a tenant that has the data trait targeted for optimization. The processor determines an optimal query plan based on the original query and synthetic statistics. Finally, the processor executes the original query based on the optimal query plan.