Want to use notablescan on the production DB.
Want to apply notablescan to per DB or per COLLECTION.
We can kill our mongod easily by sending query with no indexed field to the more than hundreds GB of collection.
To make matters worse, we'll get same results by specifying non-existent field cause by simple typo.
The feature of notablescan option can prevent these catastrophic incidents.
Especially, on the production DB.
But currently, likely to add this sentence to mongo-docs.
+ Don't run production :program:`mongod` instances with
+ :parameter:`notablescan` because preventing table scans can potentially
+ affect queries in all databases, including administrative queries.
I think, this is the wrong policy to keep our mongo system safety.
On the contrary, I want to come to be that the notablescan option is applicable per DB or per COLLECTION.