Hi, I am trying to understand drill's performance how we can best use it for our project. We use mongo as our primary "live" database and I am looking at syncing data to Amazon S3 and using Drill to run reports off of that.
I was hoping that I could have Drill connect directly to mongo for some things. For example: Our software is used to collect responses from school classroom. I thought if I was running a report for students in a given class, I could build the list of students at a school using a query to mongodb. I wanted to verify that drill would push down filters when doing a join, maybe first collecting a list of ids it is interested and use that as a filter when it scans the next mongo collection. However, when I look at the physical plan I don't see any evidence that it would do this, it shows the filter as null in this case. I also tried a query where I filtered on createdAt > date_sub(current_timestamp, interval "1" day) and it didn't apply that as a push-down filter (according to the physical plan tab) whereas I had hoped it would have calculated the resulting timestamp and applied that as a filter when scanning the collection. Is there some rule I can use to predict when a filter will be propagated to the mongo query?
