XML Database is an open source database released by Oracle. it stores xml files in native mode, and query the stored xml files with xquery, and provides fulltext to retrieve keywords by using full text searching. It has been used widely in industry, as well as Marklogic, a well-known database vendor, is also an xml database. Here, we also dig into the internal of XML DB to show how it works.

#0. How the Query Engine Workds.

In this part, we well explain how the xml query engine works. The syntax and grammartic parser will be explained deeply.