Abstract: Computer-implemented systems and associated operating methods use performance maps created by evaluating robustness of a database operator, query plan, or query to analyze health of a currently-executing query. The computer-implemented system comprises logic that receives one or more robustness maps of measured database system performance acquired during database execution in a predetermined range of runtime conditions. The logic analyzes state of a currently-executing query by locating the query's performance on the robustness maps.

Abstract: Computer-implemented and associated operating methods evaluate robustness of a query plan by measuring performance with regard to a range of runtime conditions and producing a map of relative performance of the given query plan when compared with alternative plans for a range of conditions. The computer-implemented system comprises logic that evaluates the selected query plan in comparison to multiple alternative query plans in a predetermined range of runtime conditions that include data characteristics. The logic produces a set of performance measurements and analyzes the measured performance to map performance of the selected query plan in comparison to performance of one or more alternative query plans.

Abstract: Computer-implemented systems and associated operating methods take measurements and landmarks associated with robustness maps and perform tests evaluating the robustness of a database engine's operator implementations and/or query components. The illustrative computer-implemented system comprises logic that receives one or more robustness maps of measured database system performance acquired during database execution in a predetermined range of runtime conditions and uses information from the robustness map or maps to perform regression testing wherein landmarks in the robustness maps are operated upon as a robustness bugs describing conditions under which a predetermined implementation of a database operator or query component degrades in a manner different from a predetermined expected manner.

Abstract: Computer-implemented systems and associated operating methods use atomic query maps to identify and evaluate database query plan robustness landmarks. The computer-implemented system comprises logic that evaluates robustness of a selected atomic query by measuring performance of atomic query execution in a predetermined range of runtime conditions that include data characteristics. The logic produces a set of measurements that can be displayed as one or more performance maps and analyzes the measured performance to identify landmarks indicative of database atomic query performance degradation greater than a predetermined amount.

Abstract: A connectivity server for a collecting, arranging and representing data defining the interconnection of pages on the World Wide Web (Web). A URL Database stores URLs and associates a fingerprint and CS_id with each URL. The URL Database interface is operable to translate between any two of a URL, a fingerprint, and a Host_id. A Host Database associates a Host_id with each distinct hostname in the URL Database. The Host Database interface is operable to accept a Host_id and return a number equal to the number of URLs on the respective host and to return the CS_ids of those URLs. A Link Database stores links between source URLs and destination URLs. The Link Database interface is operable to retrieve, for a given CS_id, the number of inlinks to and outlinks from the URL corresponding to the CS_id.