More on the Gandiva Initiative here: https://www.dremio.com/announcing-gandiva-initiative-for-apa...

Yes this has changed. The BI Connector 2.0 is written in Go and uses the MySQL wire protocol: https://docs.mongodb.com/bi-connector/master/release-notes/

In 2009 I was working on building out API docs and looked around for good examples. Stripe was so far ahead of everyone else. I still think they have some of the best documentation out there.

See the docs for document validation, available in 3.2 and later.

https://docs.mongodb.com/manual/core/document-validation/

Awesome, I had no idea they'd added that!

High scale public references and links to their presentations are maintained here: http://www.mongodb.com/mongodb-scale

I think scaling any system takes careful planning.

IMHO, this is an area where MongoDB has improved a lot in the past two years, especially with 3.0, but there is still a lot of work to do.

Queries in MongoDB can return very large result sets, but you access them in batches via a cursor: http://docs.mongodb.org/manual/core/read-operations/#cursor-...

MongoDB's MapReduce implementation is not being deprecated. The primary beneficiary of the V8 implementation is MapReduce, so it should be seen as further investment in this area.

You can also run Hadoop MapReduce over data in MongoDB directly (24 - 29): http://www.slideshare.net/spf13/mongodb-and-hadoop

from: http://docs.mongodb.org/manual/reference/server-status/

serverStatus.workingSet.pagesInMemory

pagesInMemory contains a count of the total number of pages accessed by mongod over the period displayed in overSeconds. The default page size is 4 kilobytes: to convert this value to the amount of data in memory multiply this value by 4 kilobytes.

If your total working set is less than the size of physical memory, over time the value of pagesInMemory will reflect your data size. Conversely, if your data set is greater than the size of the physical RAM, this number will reflect the total size of physical RAM.

Use pagesInMemory in conjunction with overSeconds to help estimate the actual size of the working set.

Also, there's a discussion of working set in this guide starting on page 9: http://info.10gen.com/rs/10gen/images/10gen-MongoDB_Operatio...