The increasing number of XML repositories has stimulated the design of systems that can store and query XML data efficiently. OrientX, a native XML database sys tern, is designed to meet this requirement. In this pape...The increasing number of XML repositories has stimulated the design of systems that can store and query XML data efficiently. OrientX, a native XML database sys tern, is designed to meet this requirement. In this paper, we described the system structure and design of OrientX, an integrated, schema-based native XML database. The main contributions of OrientX are： a）We have implemented an integrated native XML database system, which supports native storage of XML data, and based on it we can handle XPath＆ XQuery efficiently; b）In our OrientX system, schema information is fully explored to guide the storage, optimization and query processing.展开更多
Metadata, by definition, is information associated with data, covering where, how, when and by whom the data were acquired. The chance to take part in European projects such as the EU-SeaDataNet (the Pan-European infr...Metadata, by definition, is information associated with data, covering where, how, when and by whom the data were acquired. The chance to take part in European projects such as the EU-SeaDataNet (the Pan-European infrastructure for ocean and marine data management) made it necessary to use XML (Extensible Markup Language) as a standard file format for sharing data and metadata. At present, the Italian National Oceanographic Data Centre (OGS/NODC) has all its data and metadata contained in an Oracle relational database, and the metadata is managed using XML formats and schema (XSD;XML Schema Definition), giving common vocabularies for parameters, instruments, ships, etc. in agreement with European project standards. One problem with XML is the dynamic change in metadata schemas (XSD), necessitating development of a system which is flexible and capable of managing the changes. This paper describes a system for managing oceanographic metadata using XML files and the functionalities provided by the Oracle database. To better manage the XML format, we chose to load into the OGS/NODC database the whole XML file, using a dedicated field. The database Oracle gives us the flexibility to manage the XML format locally, within the OGS/NODC information system, using the XML DB (XML DataBase) Oracle features. This, through the use of XMLType, allows the inclusion of the XML into the database. Furthermore, through the use of the XQuery functions it is possible to create a set of views through which information contained in the XML can be viewed more immediately in a relational form. Using the XML and the XQuery functions, it is possible to store, extract and manage different kinds of information that might be exchanged at the European level. Moreover, with a RESTful (Representational State Transfer) Web Service, we have a simple and standard interface for rapidly and easily creating, modifying and deleting records containing XML files inside the database. Finally, through the use of a RESTful Web Service, it is possible to decouple the application from the database, so that through the use of software that manages HTTP URLs, such as the Mikado (SeaDataNet project), the XML file can be inserted, updated and deleted inside the database without the need for a direct connection to it.展开更多
提出了一种存储方法 ,首先把 XML 文档映射为泛关系模式 ,再利用算法 Derive FDs推导出 XML 键所蕴含的泛关系模式上函数依赖集的规范覆盖 ,根据此规范覆盖 ,最后将泛关系模式保持函数依赖地分解为 3NF模式集 .得到了保持 XML 键约束的...提出了一种存储方法 ,首先把 XML 文档映射为泛关系模式 ,再利用算法 Derive FDs推导出 XML 键所蕴含的泛关系模式上函数依赖集的规范覆盖 ,根据此规范覆盖 ,最后将泛关系模式保持函数依赖地分解为 3NF模式集 .得到了保持 XML 键约束的规范化存储模式 ,实现了 XML 文档在关系数据库中的规范化存储 .展开更多
基金Supported by the National Natural Science Foun-dation of China (60573091 ,60273018)
文摘The increasing number of XML repositories has stimulated the design of systems that can store and query XML data efficiently. OrientX, a native XML database sys tern, is designed to meet this requirement. In this paper, we described the system structure and design of OrientX, an integrated, schema-based native XML database. The main contributions of OrientX are： a）We have implemented an integrated native XML database system, which supports native storage of XML data, and based on it we can handle XPath＆ XQuery efficiently; b）In our OrientX system, schema information is fully explored to guide the storage, optimization and query processing.
文摘Metadata, by definition, is information associated with data, covering where, how, when and by whom the data were acquired. The chance to take part in European projects such as the EU-SeaDataNet (the Pan-European infrastructure for ocean and marine data management) made it necessary to use XML (Extensible Markup Language) as a standard file format for sharing data and metadata. At present, the Italian National Oceanographic Data Centre (OGS/NODC) has all its data and metadata contained in an Oracle relational database, and the metadata is managed using XML formats and schema (XSD;XML Schema Definition), giving common vocabularies for parameters, instruments, ships, etc. in agreement with European project standards. One problem with XML is the dynamic change in metadata schemas (XSD), necessitating development of a system which is flexible and capable of managing the changes. This paper describes a system for managing oceanographic metadata using XML files and the functionalities provided by the Oracle database. To better manage the XML format, we chose to load into the OGS/NODC database the whole XML file, using a dedicated field. The database Oracle gives us the flexibility to manage the XML format locally, within the OGS/NODC information system, using the XML DB (XML DataBase) Oracle features. This, through the use of XMLType, allows the inclusion of the XML into the database. Furthermore, through the use of the XQuery functions it is possible to create a set of views through which information contained in the XML can be viewed more immediately in a relational form. Using the XML and the XQuery functions, it is possible to store, extract and manage different kinds of information that might be exchanged at the European level. Moreover, with a RESTful (Representational State Transfer) Web Service, we have a simple and standard interface for rapidly and easily creating, modifying and deleting records containing XML files inside the database. Finally, through the use of a RESTful Web Service, it is possible to decouple the application from the database, so that through the use of software that manages HTTP URLs, such as the Mikado (SeaDataNet project), the XML file can be inserted, updated and deleted inside the database without the need for a direct connection to it.
文摘提出了一种存储方法 ,首先把 XML 文档映射为泛关系模式 ,再利用算法 Derive FDs推导出 XML 键所蕴含的泛关系模式上函数依赖集的规范覆盖 ,根据此规范覆盖 ,最后将泛关系模式保持函数依赖地分解为 3NF模式集 .得到了保持 XML 键约束的规范化存储模式 ,实现了 XML 文档在关系数据库中的规范化存储 .
