Most veteran developers must have experienced a rather low database I/O performance. However, many may not have a full understanding of how slow the I/O operation is, particularly about the gap between database I/O speed and the speeds of other data read/write methods.

Java is a commonly used technique used for application development. In this article, we perform a field test to find out the performances of retrieving data from Oracle and MySQL – the two typical types of databases in Java, and compare them with the performance of retrieving data from the text file.