About performance of FoundationDB:
PostgreSQL drivers compatibility
The SQL Layer “speaks” the PostgreSQL protocol. Therefore, any PostgreSQL client driver can be used to connect to any SQL Layer instance. Almost every language has such a driver and a complete list is maintained at the Software Catalogue - Drivers and interfaces section of the PostgreSQL documentation.
One important difference is that the SQL Layer exposes standard metadata tables <information-schema-index> whereas Postgres has pg_xxx System Catalogs tables, and as a result some drivers relying on metadata queries will log errors on startup. If you’re trying to use or fork a driver or ORM not listed here, check out the troubleshooting untested drivers and ORMs section below.
I have begun to try to transit to FoundationDB,
cause it uses Postgres protocol, I have made some changes to Zabbix Frontend and it works, sure with mistakes, but all reads work and users update.
I know you work about mid-layer between Zabbix and NoSQL databases what about to add FoundationDB.