#mongodb shell

$ mongo test --eval "var collection = 'users'" variety.js

The above is executed from terminal."test" is the database containing the collection we are analyzing.

Variety's output:

{ "_id" : { "key" : "_id" }, "value" : { "types" : [ "object" ] }, "totalOccurrences" : 4, "percentContaining" : 100 } { "_id" : { "key" : "name" }, "value" : { "types" : [ "string" ] }, "totalOccurrences" : 4, "percentContaining" : 100 } { "_id" : { "key" : "bio" }, "value" : { "types" : [ "string" ] }, "totalOccurrences" : 3, "percentContaining" : 75 } { "_id" : { "key" : "pets" }, "value" : { "types" : [ "string", "array" ] }, "totalOccurrences" : 2, "percentContaining" : 50 }

{ "_id" : { "key" : "someWeirdLegacyKey" }, "value" : { "type" : "string" }, "totalOccurrences" : 1, "percentContaining" : 25 }

Every document in the “users” collection has a "name" and "_id". Most, but not all have a "bio". Interestingly, it looks like "pets" can be either an array or a string. The application code really only expects arrays of pets. Have we discovered a bug, or a remnant of a previous schema?

The first document created has a weird legacy key I've never seen before- the people who built the prototype didn't clean up after themselves. These rare keys, whose contents are never used, have a strong potential to confuse developers, and could be removed once we verify our findings.

For future use, results are also stored a varietyResults database.

Learn More!

Learn more about Variety now, including

• How to download Variety

• How to set a limit on the number of documents analyzed from a collection

• How to contribute, and report issues

Variety is free, open source, and written in 100% JavaScript. Check it out on Github.