1. A database engine implemented in a computer system coupleable to a database store that provides for the storage of a database table, said database engine being operative in responsive to database query requests relative to said database table to return a current sequence of data tuples corresponding to a predetermined database query request, said database engine comprising: i) a write-store structure that provides for the storage of data tuple updates pending application to said database table; and ii) a merge scan processor, coupled to said write-store structure, operative to retrieve from said database table an initial sequence of data tuples responsive to said predetermined database query request, said merge scan processor being further dynamically operative to selectively merge said data tuple updates with said initial sequence of data tuples to provide said current sequence of data tuples.