Data Skew
NURand - Non Uniform Random
- NURand(A,x,y) = (((random(0,A) | random(x,y)) + C) % (y-x+1)) + x
- Customer Last Name: NURand(255, 0, 999)
- Customer ID: NURand(1023, 1, 3000)
- Item ID: NURand(8191, 1, 100000)
- bitwise OR of two random values
- skews distribution toward values with more bits on
- 75% chance that a given bit is one (1 - ½ * ½)
- skewed data pattern repeats with period of smaller random number