Título: | EXPERIMENTAL STUDY OF CONJUNCTIVE QUERIES OPTIMIZATION WITH EXPENSIVE PREDICATES | ||||||||||||||||||||||||||||||||||||
Autor: |
RODRIGO SILVA GUARINO |
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Colaborador(es): |
EDUARDO SANY LABER - Orientador |
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Catalogação: | 12/JUL/2004 | Língua(s): | PORTUGUESE - BRAZIL |
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Tipo: | TEXT | Subtipo: | THESIS | ||||||||||||||||||||||||||||||||||
Notas: |
[pt] Todos os dados constantes dos documentos são de inteira responsabilidade de seus autores. Os dados utilizados nas descrições dos documentos estão em conformidade com os sistemas da administração da PUC-Rio. [en] All data contained in the documents are the sole responsibility of the authors. The data used in the descriptions of the documents are in conformity with the systems of the administration of PUC-Rio. |
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Referência(s): |
[pt] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=5170&idi=1 [en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=5170&idi=2 |
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DOI: | https://doi.org/10.17771/PUCRio.acad.5170 | ||||||||||||||||||||||||||||||||||||
Resumo: | |||||||||||||||||||||||||||||||||||||
Traditional database query optimization technique have as
its
main heuristic the organization of predicates in two main
types: selection
predicates and join predicates. Join predicates are
considered much more
expensive than selection predicates. In additional, it's
also considered that there's no big difference among the
costs of different selection predicates,
what makes the optimizer executes them first in any order,
reducing the number of tuples necessary to execute join
predicates.This assumption, that is well applied in
traditional database applications, becomes invalid
in respect of recent database applications, that executes
complex functions over complex data in selection
predicates. In this cases, selection predicates
are considered more expensive than join predicates and
their costs cannot be considered equivalent anymore. This
makes the main heuristic of push down selections invalid
for these kind of new selection predicates which calls for
new optimization techniques. These type of cue named
expensive predicates. This work has two main objectives:
Present a software that makes possible the development,
test and integrat analisys of different algorithms for
evaluating expensive predicates and analyse the performance
of four algorithm's implementations that are based on
Cherry Picking strategy, which aims at exploring the data
dependency between input values to expensive predicates.
The experiments considered conjunctive(AND) queries, and
the general idea is to try evaluate the attributes in a
order that minimizes the general cost of the tuples.
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