Add a new thread variable blind_delete_primary_key:
"Deleting rows by primary key lookup, without reading rows (Blind Deletes)."
" Blind delete is disabled if the table has secondary key"
The feature is implemented at https://github.com/facebook/mysql-5.6/commit/f15fcf28391d6e222b26c2332e7c3c9ac90965fc
Investigate how to take in Facebook MyRocks blind delete