Recursive XML Schemas, Recursive XML Queries, and Relational Storage: XML-to-SQL Query Translation

This paper considers the problem of translating XML queries into SQL when XML documents have been stored in an RDBMS using a schema-based relational decomposition. Surprisingly, there is no published XML-to-SQL query translation algorithm for this scenario that handles recursive XML schemas. This paper presents a generic algorithm to translate path expression queries into SQL in the presence of recursion in the schema and queries. This algorithm handles a general class of XML-to-Relational mappings, which includes all techniques proposed in literature.