Project/Area Number |
20500043
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Software
|
Research Institution | National Institute of Informatics |
Principal Investigator |
KATO Hiroyuki National Institute of Informatics, コンテンツ科学研究系, 助教 (10321580)
|
Project Period (FY) |
2008 – 2010
|
Project Status |
Completed (Fiscal Year 2010)
|
Budget Amount *help |
¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
Fiscal Year 2010: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2009: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2008: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
|
Keywords | アルゴリズム / 関数系言語 / 融合変換 / XQuery / データ統合 / 最適化 / XML / 関数型言語 / プログラム変換 / モナド |
Research Abstract |
Fusion is a known technique for eliminating unnecessary intermediate results that are created but then consumed during computation. Being useful for query optimization for many query languages such as SQL, fusion remains as a challenge for XQuery optimization. This is because XQuery has more complicated semantics ; it is context sensitive and requires preservation of document order. In this research, we proposed, as far as we are aware, the first XQuery fusion that can deal with both the document order and the context of XQuery expressions. More specifically, we carefully designed a context representation of XQuery expressions based on the Dewey order encoding, developed a context-preserving XQuery fusion for ordered trees by static emulation of the XML store, and proved that our fusion is correct. Our XQuery fusion has been implemented and successfully applied to the multi-step schema mapping, in which fusion is particularly necessary for reducing execution cost of redundant node creations.
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