In Oracle database development, which approach best describes how you can load data from an XML file into an Oracle table?

Introduction / Context:
Modern Oracle databases provide powerful support for XML through Oracle XML DB. Loading data from XML files into relational tables is a common task when integrating with external systems or processing configuration and reference data. Interview questions about this topic check whether you understand the high level approach to mapping hierarchical XML data to relational structures rather than expecting code level details.

Given Data / Assumptions:

• An XML file contains structured data that should populate one or more Oracle tables.
• We are working with an Oracle database that supports XMLType and XML DB features.
• The question asks for the best description of a typical approach, not a specific script.

Concept / Approach:
Oracle supports XML natively through the XMLType data type and related SQL and PL/SQL functions. A common pattern is to load the XML document into an XMLType column or variable, and then use XMLTABLE, EXTRACT, or similar functions to project parts of the XML into relational columns. This process is often called shredding the XML, because it breaks the hierarchical structure into rows and columns suitable for relational tables. This approach is more robust and maintainable than manual copy pasting or file renaming tricks.

Step-by-Step Solution:
Step 1: Place the XML file where Oracle can access it, such as in a directory object or as a CLOB or BFILE. Step 2: Use Oracle features to load the file content into an XMLType instance, either in a staging table or directly in a query. Step 3: Use the XMLTABLE function in a SELECT statement to map XML paths to relational columns, effectively turning nodes into rows. Step 4: Wrap the XMLTABLE based SELECT in an INSERT INTO or MERGE statement to populate the targeted relational table with data extracted from the XML. Step 5: Optionally validate the XML against a schema and handle errors or missing data as part of the loading process.

Verification / Alternative check:
Oracle documentation and examples demonstrate this pattern using XMLType and XMLTABLE. For instance, you may see statements like INSERT INTO customers (...) SELECT ... FROM XMLTABLE(...) that extract attributes and elements from an XML document stored in an XMLType column. These examples confirm that Oracle XML DB features are designed exactly for the purpose of loading XML data into relational structures.

Why Other Options Are Wrong:
Option A is wrong because manually pasting XML content into rows is error prone, not scalable, and not the intended way to integrate XML with Oracle. Option B is incorrect because merely referencing the XML file as an external resource does not load data into Oracle tables; it also fails to take advantage of XML parsing and mapping. Option D is clearly wrong because changing the file extension to .db has no effect on how Oracle interprets or loads data; Oracle uses defined tools and data types, not file name tricks.

Common Pitfalls:
A common pitfall is trying to treat XML files like flat files and using tools such as SQL Loader without considering the hierarchical structure, which can lead to complex and fragile control files. Another mistake is ignoring XML schema validation and assuming that all incoming XML will match the expected format. Using XMLType, XMLTABLE, and related functions helps you model XML correctly and maintain proper mappings between the XML structure and relational tables.

Final Answer:
The recommended approach is to use Oracle XML DB features such as the XMLType data type together with XMLTABLE or related functions to shred XML elements into relational columns during INSERT or MERGE operations.