Re:How to make MongoDB not suck for analytics
by naranha on Monday July 02, 2018 @09:35AM
(#17441474)
> Then there are client-side joins.
AKA what you are doing when writing your SPAs with their own state management. Server-side joins rarely make sense in that context.
For reporting/analytics.. yes. But these can be delegated to external system/databases optimized for that task. With elasticsearch for example you get very far very quickly without the need to write any SQL joins.
Would you suggest elasticsearch over sql for analytics like these? We're actually looking at a very similar situation, and I have a hard time believing aggregations in elasticsearch (especially when no full text indexes are required) are a better fit than sql. That could be my lack of experience with elastic though.
It can join with the $lookup function these days. Although it is only to a "non-sharded collection". I don't know why it can't join to a sharded collection when the join is on the same shard though.
There is also the option of using $in with a list of things you have pulled down in another query.
Then there are client-side joins.