Distributed Query Optimization in the Stack-Based Approach

Kozankiewicz, Hanna; Stencel, Krzysztof; Subieta, Kazimierz

doi:10.1007/11557654_101

Cited by 14 publications

(10 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…There are some methods for distributed query processing in a distributed environment, and local query generation is one of the popular and basic methods [4,5,6,7]. XQuery is a natural choice for integrating heterogeneous data with XML data because XQuery is a standard query language for XML data.…”

Section: Related Workmentioning

confidence: 99%

Local Query Generation for Distributed XQuery Queries

Park

Kang

2010

2010 International Conference on Cyber-Enabled Distributed Computing and Knowledge Discovery

View full text Add to dashboard Cite

XML view is proposed to integrate between XML data and heterogeneous data over distributed environment and global XML view is used to search distributed heterogeneous data. Distributed XQuery queries based on a global XML view can search heterogeneous data seamlessly, being distributed in the local systems. One of the basic and simple methods to process distributed SQL queries is that generates local SQL queries for processing a distributed SQL query and constructs the result of the distributed query from the results of the local queries. Therefore, it is natural to consider how the method for distributed SQL queries can be applied to processing XQuery queries. However, the syntax of XQuery differs from SQL because the XQuery contains some special expressions like FOR clauses for querying to semi-structured data. Therefore, this paper defines some problems to generate local XQuery queries for processing distributed XQuery queries and proposes a method for generating local XQuery queries considered these problems. We also implement a distributed XQuery query processor using our method.

show abstract

Section: Related Workmentioning

confidence: 99%

Local Query Generation for Distributed XQuery Queries

Park

Kang

2010

2010 International Conference on Cyber-Enabled Distributed Computing and Knowledge Discovery

View full text Add to dashboard Cite

show abstract

“…Decomposing queries to address multiple data sources is by now a well-studied problem in relational databases [28] and object-oriented databases [13], [17]. Many of these ideas and methods can be applied to XQUERY, yet we have shown here that the issue of efficiently managing distributed node identity and document order add interesting challenges.…”

Section: Evaluation In Monetdb/xquerymentioning

confidence: 99%

“…Decomposing queries to address multiple data sources is a well-studied optimization problem in relational [28], objectoriented [13], [17], and semi-structured databases [24], [25]. While it is natural (and true) to assume that many of the existing techniques can be carried over, the XML data model and the XQUERY language introduce a number of particular challenges not met elsewhere, that revolve around XML node identity and structural (rather than value-based) relationships between nodes.…”

Section: Introductionmentioning

confidence: 99%

Efficient Distribution of Full-Fledged XQuery

Zhang

Tang

Boncz

2009

2009 IEEE 25th International Conference on Data Engineering

View full text Add to dashboard Cite

Abstract-We investigate techniques to automatically decompose any XQuery query into subqueries, that can be executed near their data sources; i.e., function-shipping. In this scenario, the subqueries being executed remotely may have XML nodevalued parameters or results, that must be shipped in some way. The main challenge addressed here is to ensure that the decomposed queries properly respect XML node identity and preserve structural properties, when (parts of) XML nodes are sent over the network, effectively copying them.We start by precisely characterizing the conditions, under which pass-by-value parameter passing causes semantic differences between remote execution of an XQuery expression and its local execution. We then formulate a conservative strategy that effectively avoids decomposition in such cases. To broaden the possibilities of query distribution, we extend the pass-byvalue semantics to a pass-by-fragment semantics, which keeps better track of node identities and structural properties. The pass-by-fragment semantics is subsequently refined to a pass-byprojection semantics by means of a novel runtime XML projection technique, which safely eliminates most semantic differences between the local and remote execution of an XQuery expression, and strongly reduces message sizes.The proposed techniques are implemented in XRPC, a simple yet efficient XQuery extension that enables function-shipping by adding a Remote Procedure Call mechanism to XQuery. Experiments on MonetDB/XQuery establish the performance potential of our XQuery decomposition techniques.

show abstract

“…특별히 분산 환경에서 전역 XQuery 질의를 처리하기 위한 방법은 현 재 연구 중에 있으며, 기존에 존재하는 분산 SQL과 같은 질의 어를 처리하기 위한 방법으로부터 그 해결 방법을 찾기 위한 노력들이 존재한다 [5]. 전통적인 데이터베이스 질의인 SQL 질 의의 경우, 전역 SQL 질의의 처리를 위해 사용되고 있는 대표 적이고 기본적인 방법들 가운데 하나는 전역 질의를 분할하여 지역 시스템을 위한 지역 질의들을 생성하고, 지역 질의들의 결과로부터 전역 질의의 결과를 취하는 방법이다.…”

unclassified

“…전통적인 데이터베이스 질의인 SQL 질 의의 경우, 전역 SQL 질의의 처리를 위해 사용되고 있는 대표 적이고 기본적인 방법들 가운데 하나는 전역 질의를 분할하여 지역 시스템을 위한 지역 질의들을 생성하고, 지역 질의들의 결과로부터 전역 질의의 결과를 취하는 방법이다. 이러한 방 법은 지역 시스템의 어떠한 정보도 참조할 필요 없이 전역 질 의를 처리할 수 있는 가장 간단한 방법이며, 향후 동적인 질의 처리 방법으로의 확장이 용이한 방법이므로 전역 XQuery 질 의의 처리를 위해서도 반드시 연구되어야 할 방법들 가운데 하나이다 [5,6,7]. 그러나 XQuery 질의는 구조적 문서인 XML 문서의 검색을 그 목적으로 하는 질의어이므로 그 특성이 SQL과는 적지 않은 차이가 존재할 뿐만 아니라 질의어 자체 의 복잡도 또한 매우 높은 언어이다 [7,8] <items><item id="item0"><feature> <description>A is~~</description> <color>red</color> </feature> <URI>URI1</URI><URI>URI2</URI> <owner>Park</owner> </item> <item id="item1"><feature> <description>B is~~</description> <color>red</color></feature> <URI>URI3</URI><owner>Park</owner> </item> <item id="item2"><feature> <description>C is~~</description> <color>Blue</color></feature> <URI>URI4</URI><owner>Lee</owner> </item></items> seller.xml <sellers> <seller id="person0"> <name>Park</name> <address>Daejeon</address> <address>Seoul</address> </seller> <seller id="person1"> <address>Incheon</address> <name>Kim</name> </seller> </sellers> 표 1.…”

unclassified

A Global XQuery Query Processing based on Local XQuery Query Generation

Park¹,

Park²,

Kim³

et al. 2010

Journal of the Korea Society of Computer and Information

View full text Add to dashboard Cite

XML view is proposed to integrate between XML data and heterogeneous data over distributed environment and global XML view is used to search distributed heterogeneous data. At this time, standard query language for user is XQuery and the method for processing global XQuery queries over distributed environment is one of the new research topics. One of the basic and simple methods to process distributed SQL queries is that generates local queries for processing a global query and constructs the result of the global query from the results of the local queries. However, the syntax of XQuery differs from SQL because the XQuery contains some special expressions like FOR clauses for querying to semi-structured data, of course, FOR clauses are not used in SQL.

show abstract

Distributed Query Optimization in the Stack-Based Approach

Cited by 14 publications

References 8 publications

Local Query Generation for Distributed XQuery Queries

Local Query Generation for Distributed XQuery Queries

Efficient Distribution of Full-Fledged XQuery

A Global XQuery Query Processing based on Local XQuery Query Generation

Contact Info

Product

Resources

About