I've never used NOSQL databases before, but so far it seems like the best data storage solution for my project.

I am going to implement a datamining application. The data I would like to mine is thousands of documents which cannot be imported into datamining applications. To make to import easier and faster (than importing thousands of documents) I am planning to import these documents into a NOSQL database first and when import NOSQL database into datamining software. At the very least once I have all the data in NOSQL database I should be able to code simplest datamining logic myself.

Am I correct that NOSQL databases allow to creates records of data, but they don't mandate all the records to adhere to the same data schema (same column names/types in a classic table oriended SQL databases)?

I think for each document I would create a row/entry/object (not sure what is the correct term is in use in NOSQL world) which would be a string id, few (columns) with unstructured text data, and a dozens of columns mostly of datetime and integer types.

From its name NOSQL does not support SQL query syntax, but it support locating the object(row/entry?) by its unique id. Does NOSQL support qyuering objects using property=value syntax?

Unfortunately most of free NOSQL db only support Java/C++ clients, which free NOSQL db would you recommend for a C# programmer?