title: What slows down growing database performance?
body: <p>I'm creating a database, and prototyping and benchmarking first.  I am using H2, an open-source, commercially free, embeddable, relational, java database.  I am not currently indexing on any column.</p>
  
  <p>After the database grew to about 5GB, its batch write speed doubled (the rate of writing was slowed 2x the original rate).  I was writing roughly 25 rows per milliseconds with a fresh, clean database and now at 7GB I'm writing roughly 7 rows/ms.  My rows consist of  a short, an int, a float, and a byte[5].  </p>
  
  <p>I do not know much about database internals or even how H2 was programmed.  I would also like to note I'm not badmouthing H2, since this is a problem with other DBMSs I've tested.  </p>
  
  <p>What factors might slow down the database like this if there's no indexing overhead?  Does it mainly have something to do with the file system structure?  From my results, I assume the way windows XP and ntfs handle files makes it slower to append data to the end of a file as the file grows.  </p>