1. A computer program product comprising a computer readable medium having computer usable program code programmed for skipping XML index scans with common ancestors of a previously failed predicate, the operations of the computer program product comprising: receiving an XML query comprising search predicates for locating information in an XML document; selecting entries from an XML document index such that the selected entries satisfy at least one predicate of the XML query, the index generated from the XML document using an XML query expression, the index comprising entries that describe paths to values of the XML document; evaluating each of the selected entries to determine whether a selected entry satisfies the remaining predicates of the XML query, the remaining predicates being different from the at least one predicate of the XML query; determining a selected entry that fails one of the remaining predicates; and skipping entries from the set of selected entries, the skipped entries having an ancestor XML node at a hierarchical level and position that matches an ancestor XML node at the hierarchical level and position of the associated selected entry that fails one of the remaining predicates.