PostgreSQL 10 introduced the concept of XML Table where we can store full XML Document.
We can retrieve the XML Document in a tabular format.

In the ETL process, we can extract XML files and directly stores into a relational table format. Later, we can apply any filters on it.

Check the below simple demonstration on this:

Create a sample XML Table:

CREATE TABLE tbl_Students AS SELECT xml
$$              
<students>
 <class id="A">
  <name>Anvesh</name>
  <subjects>
   <subject name="English"></subject>
   <subject name="Computer"></subject>
  </subjects>
  </class>
 </students>
 $$ AS Students;

Get XML data into Tabular format:

SELECT xmltable.*
  FROM tbl_Students,
       XMLTABLE ('/students/class/subjects/subject' PASSING Students
                 COLUMNS
                    id FOR ORDINALITY,
                    Student_Name text PATH '../../name' NOT NULL
                 	,Subject_Name text PATH '@name'
                );

Result:

id   |  student_name   |   subject_name
______________________________________________
 1    |  Anvesh         |   English
 2    |  Anvesh         |   Computer