https://docs.oracle.com/en/database/oracle/oracle-database/12.2/refrn/ALL_JSON_DATAGUIDES.html
ALL_JSON_DATAGUIDES
ALL_JSON_DATAGUIDES provides information on the JavaScript Object Notation (JSON) columns accessible to the current user that have data guide enabled.
json
https://epub.ub.uni-muenchen.de/14875/
Content-Aware DataGuides for Indexing Large Collections of XML Documents
content awarelarge collectionsindexingxmldocuments