A computer-implemented method for querying a data source using an optimized exclusion filter expression created from a full filter expression is described. The method includes receiving one or more queries defined by the full filter expression, wherein the one or more queries are for obtaining an output from the data source; performing a reduction on the full filter expression to determine the optimized exclusion filter expression; applying the optimized exclusion filter expression in the data source to exclude data; and applying the full filter expression to data not excluded by the optimized exclusion filter expression.