Abstract: Various embodiments of systems and methods for tracking queries and retrieved results are described herein. In one aspect, a first query is associated with a first result set in a first tuple and a second query is associated with a second result set in a second tuple. The first result set is retrieved based on the execution of the first query and the second result set is retrieved based on the execution of the second query. The first and the second tuples are retained in a data structure in the order of execution of the respective queries. The retrieved result sets may be accessed forwards or backwards along the data structure without re-execution of the queries.

Abstract: Various embodiments of systems and methods for tracking queries and retrieved results are described herein. In one aspect, a first query is associated with a first result set in a first tuple and a second query is associated with a second result set in a second tuple. The first result set is retrieved based on the execution of the first query and the second result set is retrieved based on the execution of the second query. The first and the second tuples are retained in a data structure in the order of execution of the respective queries. The retrieved result sets may be accessed forwards or backwards along the data structure without re-execution of the queries.

Abstract: The invention relates to a canister comprising a first container (concentrate chamber) holding a concentrate, and a second container (solution chamber) holding a ready-to-use solution constituted by mixing a concentrate and a diluting fluid. According to the invention, the two containers of the canister are configured as chambers of the canister, connected to each other by a fluid jet pump, and can be operated from one side. Both the filling device of the concentrate chamber and the dispensing device of the chamber holding the ready-to-use solution are fitted with coded access control devices. The chambers are arranged partially above each other. The concentrate filling device and the fluid jet pump include a suction pipe and mixture outlet arranged in a canister lid.