When I reading haystack document, I got Haystack is very Model-based and doesn’t work well outside of that use case.. What is model based search and model based data. Does google or bing search engine make model search? Thanks for your consideration.
https://docs.djangoproject.com/en/dev/topics/db/models/
A model is the single, definitive source of data about your data. It contains the essential fields and behaviors of the data you’re storing. Generally, each model maps to a single database table.
Basically a model is a class that contains data and methods that relate to certain data from a data source i.e. a database table.
Does google or bing search engine make model search?
No. Not that I'm aware of. Google uses it's own index of your site and doesn't offer a way of using data from your database.
https://developers.google.com/custom-search/docs/api
The same goes for Bing. These are different from Solr or ElasticSearch which get implemented on your server and can access data in your database through an API. Whereas Google and Bing have APIs which simply allow you to use their search engine's cache of your website.