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Ihab Ilyas University of Waterloo http://www.cs.uwaterloo.ca/~ilyas. Current Projects/Areas. Ranking Uncertain Databases Relational Query Optimization. (1) Ranked Retrieval. Ordering as a first class construct in query processing The Rank-join operators
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Ihab Ilyas University of Waterloo http://www.cs.uwaterloo.ca/~ilyas
Current Projects/Areas • Ranking • Uncertain Databases • Relational Query Optimization
(1) Ranked Retrieval • Ordering as a first class construct in query processing • The Rank-join operators • A set of rank-aware physical join operators for optimal rank aggregation [VLDB’02, VLDB’03] • Cost estimation and query optimization that treats ranking as a logical property [SIGMOD’04, SIGMOD’05] • Mid-query reoptimization of ranking queries[TODS’06] • Ranking Aggregates • Top-k groups based on aggregate values [SIGMOD’06] • Top-k bargaining solution in Web interaction scenarios[ICDE’07] • Inverse Ranking Queries [in progress]
SORT H.Price + S.Tuition H.Price + S.Tuition H.Location = S.Location Thousands of Ranked Pairs !! H.Location = S.Location (1) Ranked Retrieval want to pay the minimum for a house and school tuition in the same location!! TOP (10) HOUSES SCHOOLS S H
New Rank-join operators 2-dimenional enumeration (1) Ranked Retrieval RankSQL (rank-aware algebra and optimization)
(2) Uncertain Databases • New definitions of top-k queries under possible world semantics: (I’ll talk bout it in this seminar) • The most probable top-k queries [ICDE’07] • URank: demo prototype [SIGMOD’07] • Probabilistic nearest-neighbor queries • Probabilistic Data Cleaning [in progress]
(2) Uncertain Databases URank (processing of probabilistic ranking queries)
(3) Query Optimization • MetaOptimizer: Estimating the compilation time for query optimizers [SIGMOD’03] • CORDS: Data-driven tool for discovering statistically correlated columns and recommend column groups statistics [SIGMOD’04] and demo [VLDB’04] • JITS: Just-in-Time Statistics Collection [ICDE’07] • Recommending Statistical Views [in progress]