How to search HUGE XML with DOM?

[Sullivan WxPyQtKinter]

a relation database has admiring search efficiency when the database is
very big (several thousands or tens of thousands of records). But my
current project is based on XML, for its tree-like data structure has
much more flexibility; and DOM, which could be manipulated just like a
tree. However, how to establish such a XML data base for search when it
contains 10,000 records (One record usually contain 10~30 tags) or
more?

My search needs:
1. Search and return all the record (an element) with specific id.
2. Search and return all the record whose child nodes has a specific id
or attribute.

the xml.dom.minidom object is too slow when parsing such a big XML file
to a DOM object. while pulldom should spend  quite a long time going
through the whole database file. How to enhance the searching speed?
Are there existing solution or algorithm? Thank you for your
suggetion...