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» Performing grouping and aggregate functions in XML queries
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WWW
2009
ACM
14 years 5 months ago
Performing grouping and aggregate functions in XML queries
Since more and more business data are represented in XML format, there is a compelling need of supporting analytical operations in XML queries. Particularly, the latest ver
Huayu Wu, Tok Wang Ling, Liang Xu, Zhifeng Bao
WWW
2008
ACM
13 years 11 months ago
Divide, Compress and Conquer: Querying XML via Partitioned Path-Based Compressed Data Blocks
We propose a novel Partition Path-Based (PPB) grouping strategy to store compressed XML data in a stream of blocks. In addition, we employ a minimal indexing scheme called Block S...
Wilfred Ng, Ho Lam Lau, Aoying Zhou
ICDT
2010
ACM
219views Database» more  ICDT 2010»
14 years 8 months ago
Aggregate Queries for Discrete and Continuous Probabilistic XML
Sources of data uncertainty and imprecision are numerous. A way to handle this uncertainty is to associate probabilistic annotations to data. Many such probabilistic database mode...
Serge Abiteboul, T.-H Hubert Chan, Evgeny Kharlamo...
KAIS
2006
247views more  KAIS 2006»
13 years 11 months ago
XCQ: A queriable XML compression system
XML has already become the de facto standard for specifying and exchanging data on the Web. However, XML is by nature verbose and thus XML documents are usually large in size, a fa...
Wilfred Ng, Wai Yeung Lam, Peter T. Wood, Mark Lev...
VLDB
1994
ACM
114views Database» more  VLDB 1994»
14 years 3 months ago
Including Group-By in Query Optimization
In existing relational database systems, processing of group-by and computation of aggregate functions are always postponed until all joins are performed. In this paper, we presen...
Surajit Chaudhuri, Kyuseok Shim