Question: So I just noticed one of my table have been dropped/deleted, I am using MySQL anyway I can trace or see logs of this?

I have no idea where to start look.

Answer: 
yes, it seems you need random shuffle of your cards. You could implement your version of simple [Fisher-Yates](http://en.wikipedia.org/wiki/Fisher-Yates_shuffle) shuffling, for example, or indeed, use `Collections.shuffle()`
```
long pattern = 0b111111;
Random r = new Random();
while (pattern != 0) {
    int n = r.nextInt(6);
    long mask = 1 << n;
    if ((pattern & mask) == 0) continue;
    pattern ^= mask;
    System.out.println("n = " + n);
}

```