Aggressive exploration can involve multiple, successive queries and visualizations. This creates difficulty scaling the resources needed to deliver fast responses. It is particularly complicated by regular rebuilding of analytic data stores, whether daily or on demand. Migrating queries using the technology described involves migrating indexed fields, known as dimensions, and quantity fields, known as measures, in the background during a query session. A session that starts in server query processing mode may switch to client query processing as enough data fields have been copied from the server to the client. When the client determines that it has enough data fields to process an incoming query, it can locally process the new query without passing it to the server. Since both the server and client are working from copies of the same read only analytic data structure, a user receives the same results from either client or the server.