Are there any methods or tools out there that **let us use what we know about the data in order to crack the encryption?**

For example let's say I get access to an encrypted database file but I know everything about it... Let's say I know it's a RDBMS, the table & field names, and the primary keys/foreign keys. Since I know the field names I also know what will be stored as boolean, string, numeric, date/time, etc. 

Would this or any other information about the data help with decryption? (Maybe the character encoding) 

I'm not talking about cracking a password that "decrypts" the file for us (like public/private key), I am wondering about decrypting the actual data.

I'm not very educated on encryption or ciphers, but I can't seem to find any information about introducing the human element into decryption. Sure it may take more time than the universe has existed to break AES encryption using a billion gpgpus processing in parallel, but this is only **brute force** -- shouldn't we be able to narrow down the the possibilities based on whether the output makes sense?

Just so I could play around with this idea, is there any software that will output the results of the keys that are tried?

I guess a better question with more scope would be, "Is there any way to narrow down our possibilities?"