TY - GEN
T1 - A randomized approach for the incremental design of an evolving data warehouse
AU - Theodoratos, Dimitri
AU - Dalamagas, Theodore
AU - Simitsis, Alkis
AU - Stavropoulos, Manos
N1 - Publisher Copyright:
© Springer-Verlag Berlin Heidelberg 2001.
PY - 2001
Y1 - 2001
N2 - A Data Warehouse (DW) can be used to integrate data from multiple distributed data sources. A DW can be seen as a set of materialized views that determine its schema and its content in terms of the schema and the content of the data sources. DW applications require high query performance. For this reason, the design of a typical DW consists of selecting views to materialize that are able to answer a set of input user queries. However, the cost of answering the queries has to be balanced against the cost of maintaining the materialized views. In an evolving DW application, new queries need to be answered by the DW. An incremental selection of materialized views uses the materialized views already in the DW to answer parts of the new queries, and avoids the re-implementation of the DW from scratch. This incremental design is complex and an exhaustive approach is not feasible. We have developed a randomized approach for incrementally selecting a set of views that are able to answer a set of input user queries locally while minimizing a combination of the query evaluation and view maintenance cost. In this process we exploit “common sub-expressions” among new queries and between new queries and old views. Our approach is implemented and we report on its experimental evaluation.
AB - A Data Warehouse (DW) can be used to integrate data from multiple distributed data sources. A DW can be seen as a set of materialized views that determine its schema and its content in terms of the schema and the content of the data sources. DW applications require high query performance. For this reason, the design of a typical DW consists of selecting views to materialize that are able to answer a set of input user queries. However, the cost of answering the queries has to be balanced against the cost of maintaining the materialized views. In an evolving DW application, new queries need to be answered by the DW. An incremental selection of materialized views uses the materialized views already in the DW to answer parts of the new queries, and avoids the re-implementation of the DW from scratch. This incremental design is complex and an exhaustive approach is not feasible. We have developed a randomized approach for incrementally selecting a set of views that are able to answer a set of input user queries locally while minimizing a combination of the query evaluation and view maintenance cost. In this process we exploit “common sub-expressions” among new queries and between new queries and old views. Our approach is implemented and we report on its experimental evaluation.
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U2 - 10.1007/3-540-45581-7_25
DO - 10.1007/3-540-45581-7_25
M3 - Conference contribution
AN - SCOPUS:84956860170
SN - 3540428666
SN - 9783540428664
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 325
EP - 338
BT - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
A2 - Kunii, Hideko S.
A2 - Jajodia, Sushil
A2 - Solvberg, Arne
PB - Springer Verlag
T2 - 20th International Conference on Conceptual Modeling, ER 2001
Y2 - 27 November 2001 through 30 November 2001
ER -