TY - GEN
T1 - Scheduling for shared window joins over data stream
AU - Hammad, Moustafa A.
AU - Franklin, Michael J.
AU - Aref, Walid G.
AU - Elmagarmid, Ahmed K.
PY - 2003
Y1 - 2003
N2 - Continuous Query (CQ) systems typically exploit commonality among query expressions to achieve improved efficiency through shared processing. Re cently proposed CQ systems have introduced window specifications in order to support unbounded data streams. There has been, however, little investigation of sharing for windowed query operators. In this paper, we address the shared execution of windowed joins, a core operator for CQ sys tems. We show that the strategy used in systems to date has a previously unreported performance flaw that can negatively impact queries with relatively small windows. We then propose two new execution strategies for shared joins. We evaluate the alternatives using both analytical model and implementation in a DBMS. The results show that one strategy, called MQT, provides the best performance over a range of workload settings.
AB - Continuous Query (CQ) systems typically exploit commonality among query expressions to achieve improved efficiency through shared processing. Re cently proposed CQ systems have introduced window specifications in order to support unbounded data streams. There has been, however, little investigation of sharing for windowed query operators. In this paper, we address the shared execution of windowed joins, a core operator for CQ sys tems. We show that the strategy used in systems to date has a previously unreported performance flaw that can negatively impact queries with relatively small windows. We then propose two new execution strategies for shared joins. We evaluate the alternatives using both analytical model and implementation in a DBMS. The results show that one strategy, called MQT, provides the best performance over a range of workload settings.
UR - http://www.scopus.com/inward/record.url?scp=85012119096&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:85012119096
T3 - Proceedings - 29th International Conference on Very Large Data Bases, VLDB 2003
SP - 297
EP - 308
BT - Proceedings - 29th International Conference on Very Large Data Bases, VLDB 2003
A2 - Selinger, Patricia G.
A2 - Carey, Michael J.
A2 - Freytag, Johann Christoph
A2 - Abiteboul, Serge
A2 - Lockemann, Peter C.
A2 - Heuer, Andreas
PB - Morgan Kaufmann
T2 - 29th International Conference on Very Large Data Bases, VLDB 2003
Y2 - 9 September 2003 through 12 September 2003
ER -