Does mongodb support non readable files? I have uploaded PDF/PST file in mongodb by mongofiles, but when retrieving it in R(BSON) and converting it to "Character" type, I couldn't find the PDF/PST file. Is it possible to upload 
PDF file or PST file? Which file formats does mongodb support (other than CSV,TSV,TXT,audio) ?
BSON has a Binary data type in which you can store anything you want. MongoDB sees it as a binary blob and does not care what type of data it is, so of course ot is possible to store PDF files. MongoDB documents are limited to 16 MB in size, so if you need to store large data, try GridFS.

http://blog.mongodb.org/post/183689081/storing-large-objects-and-files-in-mongodb