A computer-implemented method includes identifying a query, including one or more predicates and one or more branches, wherein one or more branches includes one or more legs. The computer-implemented method further includes, for each branch, in parallel: determining a risk, determining a return row threshold, estimating a number of return rows; terminating access if the return rows exceed the threshold. The computer-implemented method further includes, for each leg, in parallel: determining a leg return row threshold; accessing the leg; fetching one or more return rows into one or more leg return row pages; terminating access if the return rows exceed the threshold; intersecting one or more leg return row pages into one or more intersected leg return row pages; and applying the one or more predicates to the one or more intersected leg return row pages. The method may be embodied in a corresponding computer system or computer program product.