How to perform multi-dimensional queries in CouchDB/Cloudant

I'm a beginner with CouchDB/Cloudant and I would like some expert advice on the most appropriate method of performing multidimensional queries.

Example... My documents are like this

{
  _id: 79f14b64c57461584b152123e3924516,
  lat: -71.05204477,
  lng: 42.36674199,
  time: 1531500769,
  tileX: 5,
  tileY: 10,
  lod: 7,
  val1: 200.1,
  val2: 101.5,
  val3: 50
}

lat, lng, and time are the query parameters and they will be queried as ranges. For example fetch all the documents that have

 lat_startkey = -70 & lat_endkey = -72  AND
 lng_startkey = 50 & lng_endkey = 40  AND
 time_startkey = 1531500769 & time_endkey = 1530500000

I will also query using time as a range, and tileX, tileY, lod as exact values

For example
tileX = 5 AND
tileY = 10 AND
lod = 7 AND
time_startkey = 1531500769 & time_endkey = 1530500000

I've been reading about Views (map reduce), and I guess for the first type of query I could create a View each for time, lat, lng. My client could then perform 3 separate range queries, one against each View, and then in the client perform an intersection (inner join) of the resulting document id's. However this is obviously moving some of the processing outside of CouchDB, and I was hoping I could do this all within CouchDB itself.

I have also just found that CouchSearch (json/lucene), and n1ql exist... would these be of any help?

Solution

You should be able to use the N1QL query language for queries like this with no problems. N1QL is only available for Couchbase, not the CouchDB project that Couchbase grew out of.

For example, if I understand your first query there, you could write it like this in N1QL:

SELECT * 
FROM datapoints 
WHERE lat BETWEEN -72 AND -70 AND
      lng BETWEEN 40 AND 50  AND
      time BETWEEN 1531500769 AND 1530500000

To run such a query efficiently, you'll need an index, like this:

CREATE INDEX lat_long_time_idx ON datapoints(lat, lng, time)

You can find out more about N1QL here: https://query-tutorial.couchbase.com/tutorial/#1