1. A computer-implemented method for data quality monitoring, the method comprising: measuring, by a computer, a data quality of loaded data relative to a predefined data quality metric, wherein the loaded data is loaded from a data source that includes a data set comprising a plurality of elements, the measuring comprising: identifying delta changes in the loaded data and data quality rules relative to a previous measurement of the data quality of the loaded data; applying a logical calculus defined in the data quality rules to the identified delta changes; decomposing a selected quality rule into single terms and projecting the terms onto a tree structure stored in memory, in which each node of the tree structure stored in memory corresponds to one individual term of the selected quality rule; applying each individual data column to the tree structure resulting in an intermediary column cache stored in memory for each node containing an intermediate result of a selected operation; and updating, based on the delta change of the loaded date, the intermediary column cache of a node based on determining that the delta change of the loaded date affects content of the intermediary column cache of said node.