Database insert performance

Question

We are planning to implement a system for logging a high frequency of market ticks into a DB for further analysis. To simply get a little what kind of storage performance we can

Answer 1

How do these compare to simply logging to a flat file in the file system? If querying is done later, I'm not sure why you are bringing the data into a relational database at this time. Is there a need for transactions or multiple access to the database at all during this recording stage?