Storing and Querying XML Data in Object-Relational DBMSs

Abstract

Abstract. As the popularity of eXtensible Markup Language (XML) continues to increase at an astonishing pace, data management systems for storing and querying large repositories of XML data are urgently needed. In this paper, we investigate an Object-Relational DBMS (ORDBMS) for storing and querying XML data. We present an algorithm, called XORator, for mapping XML documents to tables in an ORDBMS. An important part of this mapping is assigning a fragment of an XML document to a new XML data type. We demonstrate that using the XORator algorithm, an ORDBMS is usually more efficient than a Relational DBMS (RDBMS). Based on an actual implementation in DB2 V.7.2, we compare the performance of the XORator algorithm with a well-known algorithm for mapping XML data to an RDBMS. Our experiments show that the XORator algorithm requires less storage space, has much faster loading times, and in most cases can evaluate queries faster. The primary reason for this performance improvement is that the XORator algorithm results in a database that is smaller in size, and queries that usually have fewer number of joins.

Storing and querying GML in object-relational databases

“…Object-Relational Database Management System (OR-DBMS) [16,17] products have all the advantages of RDBMS, furthermore, it has more expressive type system than RDBMS, and can be used to generate efficient mapping from XML data model to the constructs of the ORDBMS type system. So ORDBMS is more suitable for storing and querying XML and GML documents that may use varieties of data types.…”

“…Considering that object-relational databases [17] boast sophisticated data management facilities (e.g. concurrency control, crash recovery, and highly optimized query processors) and objectoriented features that GML schema has (e.g.…”

Integration of Weakly Heterogeneous Semistructured Data

“…Surprisingly, most XML enabled approaches do not use type apparatus of objects or suppose an existence of a schema of semistructured data expressed in DTD or XML Schema language, see, for example (Runapongsa, 2002), (Amornsinlaphachai, 2006).…”

XML-to-SQL Query Translation Literature: The State of the Art and Open Problems

“…In [19,27], parts of the XML document are stored using an XML ADT. The focus of these papers is to determine which parts of the DTD must be mapped to relations and which parts must be mapped to the XML ADT.…”

“…It is our hope that this paper will stimulate others to refine our classification and, more importantly, to improve the state of the art and to address and solve the open problems that the classification reveals. [7] [ 24,32] XS/SB SS recursive - [2,16,19,21,27] XS/SB SS tree -XP/GAV: XML Publishing, Global-as-view XP/LAV: XML Publishing, Local-as-view XS/SO: XML Storage, schema-oblivious XS/SB: XML Storage, schema-based QT: Query Translation VD: View Definition SS: Storage scheme restricted XPath 1 : child and attribute axes restricted XPath 2 : child, attribute, self and parent axes The interaction between XML and RDBMS can be broadly classified as shown in Figure 1. The main scenarios are:…”