What is best to use for best performance : XML or db??

Question

Hi

Dont know if this is the right forum so please correct me if so.
Im struggeling with a little dilemma. Is it better to use xml or db when retreiving data? The data contains a number of rules that needs to be used when reading a certain file. The rules tells how the file should be read and where the data in the file (in this case its an edifact file) eshould be stored in the db. Since the rules might change or new types of files would be added, makes it a bit difficult to hardcode all the rules directly in the code. To make it more user friendly i have made a program where its possible to make new rules or edit the existing. These rules might have to me used 100 times in a minute.
So is it better to save the rules in a xml file and the read the xml file every time an edifact file is recieved, or is it better to save the rules in a db and retreive the rules from there?
With the xml file i only have to read one time and with the db i have to read about 50 times.
What gives the best perfomance? Loading the xml file 100 times or reading 5000 records from the db in a minute??