Which is the Mongo-way of storing filters related to documents?

[steevej (Steeve Juneau)]

None of the following is JSON

@eddy_turbox

       "city=paris",
       "country=france",
       "device=web",
       "city=paris&country=france",
       "city=paris&device=web",
       "country=france&device=web",

Data is duplicated (but the first one is JSON at least)

@eddy_turbox

city: "paris",

and

@eddy_turbox

"city=paris"

Misconceptions about indexes:

@eddy_turbox

AFAIK for indexes to properly work the ordering of the fields must be strict, that is, if I added an index for country, city, device , I will be able to do this: find({country: france}) , but not this find({city: paris}) or find({city: paris, device: web}) since it won’t use the index.

Because ordering of fields in strict equality queries is not important; {city:paris,device:web} is the same query as {device:web,city:paris} and the query planner, as explained in the course, will reorder to leverage the same appropriate index. And nothing stops you from ordering your queried field in a consistent order in your back end before sending to the server.