Oracle’s PL/SQL DBMS_XMLPARSER package is a part of Oracle’s extensive suite of database technologies designed for working with XML data within the Oracle database. The FREEPARSER procedure within the DBMS_XMLPARSER package is specifically used to release the resources associated with a DOM parser, which has been previously allocated by the NEWPARSER function of the same package.


The DBMS_XMLPARSER package provides functionalities to parse XML documents and manipulate them as DOM (Document Object Model) trees. The DBMS_XMLPARSER.NEWPARSER function is used to create a new instance of a parser, which is essential for parsing XML documents. Once the parsing tasks are completed, it is a best practice to release the parser instance to free up the resources it consumes. This is where the FREEPARSER procedure comes into play.


DBMS_XMLPARSER.FREEPARSER(parser IN OUT NOCOPY dbms_xmlparser.parser);

parser: This is the parser instance previously created by DBMS_XMLPARSER.NEWPARSER. It’s passed as an IN OUT NOCOPY parameter, meaning it is modified by the procedure to release the resources.


Create a Parser Instance: First, you create a parser instance using the NEWPARSER function.

  myParser dbms_xmlparser.parser;
  myParser := dbms_xmlparser.newParser;
  -- Additional parsing operations here

Parse XML Document: Use the parser instance to parse an XML document. This involves setting the document and possibly manipulating the DOM tree.

Release the Parser: Once you are done with the XML parsing and manipulation, use FREEPARSER to release the parser instance.

  -- Assuming myParser is the parser instance you've worked with

Best Practices

Memory Management: Always free the parser after use to ensure efficient memory management within your PL/SQL applications. Not doing so can lead to memory leaks, especially in applications that deal with a large number of XML parsing operations.

Exception Handling: Implement proper exception handling around XML parsing operations to handle any errors gracefully and ensure that resources are freed even when errors occur.

Reuse of Parser Instances: While the FREEPARSER procedure is designed to free resources, consider the design of your application if you find yourself frequently creating and freeing parsers. Reusing parser instances for multiple parsing operations, where feasible, can improve performance.

In conclusion, the DBMS_XMLPARSER.FREEPARSER procedure is a crucial part of managing resources when working with XML parsing in Oracle databases. Proper use of this procedure ensures that your applications are efficient and robust, preventing resource leaks and contributing to overall application health.