> however, a lot of data like "number of teachers in school A" is aggregated and too difficult to run in real time when we render paged results.
Does this mean you're using MongoDB as a kind of query cache? Was there a compelling reason to prefer it to other common caches? Or even building an ETL/DW into your existing database infrastructure?
Not a query cache so much as a document cache. I'm actually implementing a query cache in Redis which is, imo, the greatest tool on earth :P
To be honest the decision to use mongo as a document cache was made before I realized the scope of our data needs. Mongo was the quickest/easiest solution at the time (early 2012). If I could do this over again, and we actually will be in the next 6 months, I'd either set it up in PostgreSQL/json, or throw everything in a wide column store.
Does this mean you're using MongoDB as a kind of query cache? Was there a compelling reason to prefer it to other common caches? Or even building an ETL/DW into your existing database infrastructure?