[DRILL-8453] Add XSD Support to XML Reader (Part 1)

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.21.1
• Fix Version/s: 1.22.0
• Component/s: Format - XML
• Assignee: Charles Givre
• Reporter: Charles Givre
• Created: 22/Aug/23 05:22
• Updated: 31/Oct/23 15:11
• Resolved: 31/Oct/23 15:11

Description

This PR is a part of a series to add better support for reading XML data to Drill.  One of the main challenges is that XML data does not have a way of inferring data types, nor does it have a way of detecting arrays.  

The only way to do this really well is to have a schema.  Some XML files link a schema definition file to the data.  This PR adds the capability for Drill to map XSD schema files into Drill schemas.  

The current plan is as follows: Part 1 of this PR simply adds the reader but adds no new user detectable functionality.  Part 2 will include the actual integration with the XML reader.  Part 3 will include the ability to read arrays.