Search/retrieve by a large OR query clause with Solr or Elasticsearch

Question

I have a search database of car models: "Nissan Gtr", "Huynday Elantra", "Honda Accord", etc...

Now I also have a user list and the types of cars they like user1 likes: carId:1234, carId:5678 etc...

Given user 1 I would like to return all the cars he likes, it can be 0 to even hundreads.

What the best way to model this in Solr or potentially another "nosql" system that can help with this problem.

I'm using Solr but I have the opportunity to use another system if I can and if it makes sense.

EDIT: Solr solution is to slow for Join (Maybe we can try nested). And the current MySQL solution which uses join tables has over 2 billion rows.

Answer 1

so, you just want to store a mapping between User->Cars, and retrieve the cars based on the user...sounds very simple:

1. Your docs are Users: contain id (indexed), etc fields
2. one of the field is 'carsliked', multivalued, which contains the set of car ids he likes
3. you have details about each care in a different collection for example.

4. given a user id, you retrieve the 'carsliked' field, and get the car details with a cross collection join

   You could also use nested object to store each liked car (with all the info about it) inside each user, but is a bit more complex. As a plus, you don't need the join on the query.

Solr would allow you many more things, for example, given a car, which users do like it? Elasticsearch will work exactly the same way (and probably many other tools, given how simple your use case seems).