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PODS
2004
ACM
147views Database» more  PODS 2004»
16 years 3 months ago
Flexible Time Management in Data Stream Systems
Continuous queries in a Data Stream Management System (DSMS) rely on time as a basis for windows on streams and for defining a consistent semantics for multiple streams and updata...
Utkarsh Srivastava, Jennifer Widom
PODS
2004
ACM
143views Database» more  PODS 2004»
16 years 3 months ago
Approximate Counts and Quantiles over Sliding Windows
We consider the problem of maintaining approximate counts and quantiles over fixed- and variablesize sliding windows in limited space. For quantiles, we present deterministic algo...
Arvind Arasu, Gurmeet Singh Manku
135
Voted
PODS
2004
ACM
98views Database» more  PODS 2004»
16 years 3 months ago
Processing First-Order Queries under Limited Access Patterns
We study the problem of answering queries over sources with limited access patterns. Given a first-order query Q, the problem is to decide whether there is an equivalent query whi...
Alan Nash, Bertram Ludäscher
148
Voted
PODS
2004
ACM
96views Database» more  PODS 2004»
16 years 3 months ago
Roads, Codes and Spatiotemporal Queries
We present a novel coding-based technique for answering spatial and spatiotemporal queries on objects moving along a system of curves on the plane such as many road networks. We h...
Sandeep Gupta, Swastik Kopparty, Chinya V. Ravisha...
PODS
2004
ACM
139views Database» more  PODS 2004»
16 years 3 months ago
On Preservation under Homomorphisms and Unions of Conjunctive Queries
Unions of conjunctive queries, also known as select-project-join-union queries, are the most frequently asked queries in relational database systems. These queries are definable b...
Albert Atserias, Anuj Dawar, Phokion G. Kolaitis