• Journal of Korea Multimedia Society
• /
• v.12 no.1
• /
• pp.1-15
• /
• 2009

This paper presents an assignment method of the multidimensional type inheritance indexes (MD-TIXs) to support the processing of XML queries in XML databases. MD-TIX uses a multidimensional index structure for efficiently supporting nested predicates that involve both nested element and type inheritance hierarchies. In this paper, we have analyzed the strategy of the query processing by using the MD-TIXs, and presented an assignment method of the MD-TIXs in the framework of complex queries, containing conjunctions of nested predicates, each one involving an Xpath having target types or domain types substitution. We first consider MD-TIX operations caused by updating of XML data-bases, and the use of the MD-TIXs in the case of a query containing a single nested predicate. And then, we consider the assignments of the MD-TIXs in the framework of more general queries containing nested predicates over overlapping paths that have common subpaths.

• Journal of KIISE:Databases
• /
• v.33 no.5
• /
• pp.513-525
• /
• 2006

Search results of XML keyword search are defined generally as the most specific elements containing all query keywords in the literature. The labels of XML elements and semantic information such as ontology, conceptual model, thesaurus, and so on, are used to improve the preciseness of the search results. This paper presents a hierarchical index for an efficient XML keyword query processing on the condition that returnable search concepts are defined and users' query concepts can be interpreted with the help of the semantic information. The hierarchical index separately stores the XML elements containing a keyword on the basis of the hierarchical relations of the concepts that the XML elements belong to, and makes it possible to obtain least common ancestors, which are candidates for the search results, with selectively reading the elements belonging to the concepts relevant to query concepts and without considering all the combinations of the elements having been read. This paper deals with how to organize the hierarchical index and how to process XML keyword queries with the index. In our experiment with the DBLP XML document and the XML documents in the INEX2003 test set, the hierarchical index worked well.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.17 no.6
• /
• pp.766-772
• /
• 2007

As XML is widely used, many researches on the XML storage and query processing have been done. But, previous works on path query processing have mainly focused on the storage and retrieval methods for a large XML document or XML documents had a same DTD. Those researches did not efficiently process partial match queries on the differently-structured document set. To resolve the problem, we suggested a new index structure using relational table. The method constructs the $B^+$-tree index using backward label paths instead of forward label paths used in previous researches for storing path information and allows for finding the label paths that match the partial match queries efficiently using it when process the queries.

• Journal of KIISE:Databases
• /
• v.32 no.5
• /
• pp.558-566
• /
• 2005

The XML is the new standard fir data representation and exchange on the Internet. In this paper, we describe a new approach for evaluating a path-oriented query against XML document. In our approach, we propose the Parallel Match Indexing Fabric to speed up evaluation of path-oriented query using path signature and design the parallel match algorithm to perform a match process between a path signature of input query and path signatures of elements stored in the database. To construct a structure of the parallel match indexing, we first make the binary tie for all path signatures on an XML document and then which trie is transformed to the Parallel Match Indexing Fabric. Also we use the Parallel Match Indexing Fabric and a parallel match algorithm for executing a search operation of a path-oriented query. In our proposed approach, Time complexity of the algorithm is proportional to the logarithm of the number of path signatures in the XML document.

• The KIPS Transactions:PartD
• /
• v.13D no.1 s.104
• /
• pp.1-10
• /
• 2006

This paper introduces the development XPERT(XML Query Processing Engine using Relational Technologies) which is based on relational model. In our system we have used a decomposed approach to store XML files in relational tables. XML queries are translated to SQLs according to the table schema, and then they are sent to the relational DBMS to get the results back. Our translation scheme produces AST(Abstract Syntax Tree) by analyzing XQuery expressions at first. And on traversing AST proper SQLs are generated. Translated SQLs can reduce the number of joins by using path information and utilize dewey number to preserve document originated orderings among compoments in XML. In addition we propose the efficient algorithms of XPath and XQuery translation. And finally we show the implementation of our prototype system for the functional evaluations.

• Journal of Korea Multimedia Society
• /
• v.5 no.1
• /
• pp.105-113
• /
• 2002

XML documents, which are becoming new standard for expressing and exchanging data in the Internet, don't have defined schema. It is not adequate to directly apply XML documents to the existing SQL or OQL. Research on how to extract schema for XML documents and query language is going on actively. Fer users' query, the results could be too many or too less. It is important to give the users adequate results. This paper suggests the way to extract many levelized schema according to the frequency of element occurrence in XML documents. The Schema can be reduced or extended to correspond to the users'query more flexibly.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.3
• /
• pp.1327-1335
• /
• 2011

XML is good at representing data with hierarchical and self-describing structure. There is no inherent semantics with XML. However, semantics of XML has come up with us as XML is used in wide and advanced applications. This paper surveyed semantics in XML data processing environment. XML semantics can be categorized into four groups according to its usage; structural semantics, relational semantics, extended semantics, and semantic web. Relational database is still a good alternative for storing and managing large volume of XML documents. We propose an extended relational semantics in order to exploit it in managing XML documents such as query processing.

• The Journal of Society for e-Business Studies
• /
• v.8 no.1
• /
• pp.103-111
• /
• 2003

Nowadays XML is used for exchanging information in e-Commerce, especially B2B. Necessity of XML DBMS has being increased to efficiently process XML data. So a lots of database products for supporting XML are rapidly appeared in the market. In this paper, we made an XML DBMS system based on Generic Data Model. First we developed XML Adaptor based on Generic Data Model and added it on relational DBMS for developing XML DBMS. XML Adaptor is composed of Query Convertor and XML Repository System. The Query Convertor parse commands that are for XML data manipulation and then call the relevant component of XML Repository System for relational database operation. The XML Repository System handles relational database operations such as create, delete, store, and etc. In this way we can use a relational DBMS for manipulation XML data. Therefor we can build more economically XML DBMS.

• The KIPS Transactions:PartD
• /
• v.10D no.4
• /
• pp.603-612
• /
• 2003

According to development of Web, an amount of XML documents has been increasing. So, many researches are proceeding to verify XML data coming from clients and to store or query efficiently database. In order to verify, store and query, DTD or XML Schema of XML documents is necessary. However, Schemaless XML documents couldn't be operated since they do not have either DTD or in Schema. In this paper, we extract XML schema in order to verify XML data and store or query efficiently database from either well-formed XML or XML Schemaless documents. XML Schema extracting technique which is proposed in this paper extract Schema graph using simulation and dataguide that is a extracting technique for semistructured characteristics of XML data. Also, we propose extracting technique for XML Schema using pattern tables that are considerated with Schema graph and reusability.

• Journal of Internet Computing and Services
• /
• v.7 no.4
• /
• pp.101-113
• /
• 2006

A path query is used in XML. Several index structures have been studied for processing the path query efficiently. In recent. the index schemes using suffix tree with structure join method were proposed. ViST is the most representative method among such methods. ViST processes the query using suffix tree and uses B+-tree to reduce the search time of the documents. However, it significantly degrades the search performance when processing the path query. The reason is that it regards the element that is not ancestor-descendant relation in the document as a descendent. In this paper, we propose an efficient index structure to solve the problem of ViST. The query processing method suitable to the index structure is also proposed. It is shown through various experiments that the proposed index structure outperforms the existing index structure in terms of the query processing time.