Big data services platform has important applications in the power distribution system. Massive quasi-real-time data service platform is a key data center in power grid, and a lot of valuable data is stored in the platform. The data in platform is unstructured, and cannot be selected by SQL statement. To maximize mining the data value, platform needs to integrate function that the accesses to real-time data, for this develop SQL engine based on PostgresSQL foreign data wrapper (Postgres_fdw). The SQL engine proposes a foreign table space estimation scheme and SQL resolution scheme for real-time databases in massive platforms. This access scheme provided good support for big data platform to get data from the underlying massive data service platform with an SQL way. Field function and performance tests validated the effectiveness of the engine.