Disclosed are a method, a device and/or a system of assisted query formation, validation, and result previewing in a database having a complex schema. In one aspect, a method of a query editor includes generating a data profile which includes a set of characteristics captured at various granularities of an initial result set generated from an initial query using a processor and a memory. The method determines what a user expects in the initial result set of the initial query and/or a subsequent result set of a subsequent query based on the data profile and/or a heuristically estimated data profile. The method includes enabling the user to evaluate a semantic accuracy of the subsequent query based on the likely expectation of the user as determined through the set of characteristics of the data profile. The set of characteristics may include metadata of the initial query.