Research the query optimization of distributed heterogeneous database based on hibernate

As distributed heterogeneous database multiple different physical locations, so will inevitably lead to a heterogeneous web server access to the database server response time difference, so in a distributed heterogeneous database access must be considered the database response time. This design technique based on hibernate database middleware, the middleware on the basis of the shortest waiting time in the traversal of distributed heterogeneous data sources, to shorten the waiting time user queries and reduce the burden on the server.