https://thecodebarbarian.com/enforcing-uniqueness-with-mongodb-partial-unique-indexes.html
Enforcing Uniqueness With MongoDB Partial Indexes in Node.js | www.thecodebarbarian.com
partial indexes
https://docs.yugabyte.com/stable/explore/ycql-language/indexes-constraints/partial-index-ycql/
Partial indexes in YugabyteDB YCQL | YugabyteDB Docs
Using Partial indexes in YCQL
partial indexesyugabytedbdocs
https://www.oraclefindings.com/2016/08/07/partial-indexes-11g/
How to implement partial indexes on Oracle 11g: one viable solution
Aug 8, 2016 - Implementing partial indexes on Oracle 11g is possible despite the fact that this functionality has been made available by Oracle in the release 12c
how to implementpartial indexes