[HIVE-1301] RAND() should be RAND_UNIF(); also, we should create RAND_NORM() and add options

• Type: Wish
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: UDF
• Assignee: Paul Yang
• Reporter: Adam Kramer
• Created: 12/Apr/10 21:54
• Updated: 05/Apr/11 22:04

Description

The generation of pseudorandom data is very useful, but would be even MORE useful if we had a few levers to pull.

Currently, RAND() generates a random number pulled from a uniform distribution between 0 and 1. It would be great if we could user-specify the min and max because that is a more elegant way to write code: RAND()*200+50 will generate the same thing as RAND_UNIF(min=50,max=250) but the latter is a much better way to express this in a readable manner.

Similarly, it would be useful to have non-uniform random data for statistical purposes. RAND_NORM(mean=0,sd=1)