Percona-TokuDB used to support NOAR (No Affected Rows) fast upserts (https://www.percona.com/blog/2013/02/12/fast-updates-with-tokudb/ https://www.percona.com/blog/2013/03/28/tokudb-fast-update-benchmark/)
It is already a feature request to re-enable it on the modern Percona Server and there are already branches ready for merging! (https://jira.percona.com/browse/TDB-63 https://tokutek.atlassian.net/browse/DB-871)
Please please please get this feature back in! Users could really use it!
I am seriously regretting going from an old manual tokudb patch to using Percona Server because upsert performance has tanked. NOAR has a really big impact on upsert-heavy workloads.