1. Database Change Notifications: Primitives for Efficient Database Query Result Caching Cesar Galindo-Legaria, Torsten Grabs, Christian Kleinerman, Florian Waas SQL Server Engine Microsoft Corp. Redmond, WA USA VLDB 2005, Trondheim, Norway http://www.microsoft.com/sql/2005/

2. 2 Motivation Three-tier architecture for web applications Time-to-life based approaches for caching of read-mostly dynamic results at mid-tier for performance reasons Problem: Outdated results in case of database updates DBS Clients Web server farm TitlePrice T-SQL10.00 HTTP15.00 HTTP SELECT price FROM books WHERE title = ‘T-SQL’ TitlePrice T-SQL10.00 UPDATE books SET price = 20.00 WHERE title = ‘T-SQL’ Mid-tier cache: HTTP 20.00 HTTP

3. 3 Demo Highlights “Non-materialized” indexed view for change detection –Query plan rewrite to register cached query results –Update rewrite to notify caches of changes in case of non- empty materialized view maintenance delta stream –Note: No DBMS installation necessary at the mid tier DBS Clients Web server farm TitlePrice T-SQL10.00 HTTP15.00 HTTP SELECT TitlePrice T-SQL10.00 Mid-tier cache: UPDATE 20.00 Change Notification: - cache re-run query, or - send delta 20.00 Update Plan Query Plan

4. 4 ? Questions ? Come and see the Demo!!!

5. 5 Bibliography K. Selcuk Candan, Divyakant Agrawal, Wen-Syan Li, Oliver Po, and Wang-Pin Hsiung. View Invalidation for Dynamic ContentCaching in Multitiered Architectures. In Proc. of the Int’l. Conf. on Very Large Data Bases, pages 562–573, 2002. Per- Ake Larson, Jonathan Goldstein, and Jingren Zhou. MTCache: Transparent Mid-Tier Database Caching in SQL Server. In Proc. of the IEEE Int’l. Conf. on Data Engineering, pages 177–189, 2004. Qiong Luo, Sailesh Krishnamurthy, C. Mohan, Hamid Pirahesh, Honguk Woo, Bruce G. Lindsay, and Jeffrey F. Naughton. Middle-tier database caching for e- business. In Proc. of the ACM SIGMOD Int’l. Conf. on Management of Data, pages 600–611, 2002.