There are always subtle nuances to every computer language. Recently, I found the following NaN (not a number) nuance in Java:

Bad:

if (value == Double.NaN)
    // Do something...

Good:

if (Double.isNaN(value))

    // Do something....

Below is a handy reference link about BDB JE (Berkeley Database Java Edition) locks, blocks and transactions:

• Locks, Blocks and Deadlocks

After running some tests, we were amazed by the performance of the concurrent locking mechanism in BDB JE.