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Published Articles >> Table of Contents >> Abstract
21st International Conference on Data Engineering (ICDE'05)
pp. 939-947
Predicate Derivation and Monotonicity Detection in DB2 UDB
T. Malkemus, IBM T.J. Watson Resource Center
S. Padmanabhan, IBM Silicon Valley Laboratory
B. Bhattacharjee, IBM T.J. Watson Resource Center
L. Cranston, IBM Toronto Laboratory
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DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/ICDE.2005.110
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| Abstract |
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DB2 Universal Database allows database schema designers
to specify generated columns. These generated
columns are useful for maintaining rollup hierarchy variables
in warehouses (e.g., date, month, quarter). In order
for the generated columns to be useful for query processing,
queries must automatically make use of such
columns when applicable. In particular, query predicates
on the original columns should be rewritten to
make use of the generated columns. In this paper, we describe
two main aspects of this predicate rewriting technique
that allows usage of the generated columns for a
variety of query predicate types. The first aspect, monotonicity
detection, allows for rewrites in the case of
range predicates. The second aspect, predicate derivation,
is the technique for using generating expressions
for query processing. We show the value of this technique
for providing significant performance improvement
when combined with indexing or multidimensional clustering
in DB2.
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 Additional Information
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Citation:
T. Malkemus, S. Padmanabhan, B. Bhattacharjee, L. Cranston,
"Predicate Derivation and Monotonicity Detection in DB2 UDB,"
icde,
pp. 939-947,
21st International Conference on Data Engineering (ICDE'05),
2005
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