14. A computer system, comprising: a computer that generates a data continuous Structured Query Language (SQL) query to a continuous data stream to construct a data continuous SQL process (DCSP); a database in communication with the computer, the database including a database engine that executes the DCSP in the database, wherein the DCSP is constructed from User Defined Functions (UDFs) that include relational operators in the SQL query and that express a relational transformation since the UDFs include an input value as a relation and an output value as a relation; and wherein the DCSP includes stations specified with triggering conditions and outgoing pipes, the outgoing pipes defined with a relation schema for type-preservation and with a stream key for identifying stream elements, wherein relations returned from the UDF are replicated to multiple pipes for multiple destination stations.
14. A computer system, comprising: a computer that generates a data continuous Structured Query Language (SQL) query to a continuous data stream to construct a data continuous SQL process (DCSP); a database in communication with the computer, the database including a database engine that executes the DCSP in the database, wherein the DCSP is constructed from User Defined Functions (UDFs) that include relational operators in the SQL query and that express a relational transformation since the UDFs include an input value as a relation and an output value as a relation; and wherein the DCSP includes stations specified with triggering conditions and outgoing pipes, the outgoing pipes defined with a relation schema for type-preservation and with a stream key for identifying stream elements, wherein relations returned from the UDF are replicated to multiple pipes for multiple destination stations. 17. The computer system of claim 14 , wherein the UDFs are triggered to repeatedly run by stream inputs to generate a data stream that is deposited to a stream table.