Is bitcoin subjected to DOS attack? Possible Duplicate:
  What protection does Bitcoin have against Denial of Service (DoS) attacks?  




Assume I am a malicious user, and my goal is to make bitcoin unusable.
I can simply make millions or even billions small transactions between a few of my accounts. (This for sure can be automated, and these transactions are for sure legit?)
Since bitcoin tracks every single transactions, is it subjected to DOS attack? 
The size of the transaction table on each client will eventually get huge and impossible to query or performance more tasks???
The Bitcoin client requires a transaction fee to be paid for low-priority transactions. Transactions of the kind you describe are low-priority, thus the cost of such an attack will be prohibitive.