Efficient exception handling during access plan execution in an on-line analytic processing system

Abstract

An On-Line Analytic Processing (OLAP) system converts queries into an operator tree comprised of a plurality of operators, wherein each of the operators is independently executed. When an exception is detected in one or more of the independently executed operators, the exception is propagated to the remaining operators of the operator tree by recycling empty data pages, piggybacking the detected exceptions on the recycled data pages, and sending the recycled data pages both upstream and downstream in the operator tree to the remaining operators of the operator tree. The propagated exceptions are delivered to the remaining operators, without interrupting the operators, at one or more points at which the operator normally reads or writes data from its input stream. Finally, the operators are terminated using a depth-first traversal of the operator tree.