Spark: what UUID version is used in the built-in uuid() function implementation?

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SparkSQL has the uuid() SQL built-in function.

However, neither the documentation states the UUID version nor I could find the source code, after a quick search.

I can assume that it is likely to be UUID V4.

What is the version used to implement it?

Thanks.

Bonus question: Where is it implemented in the source code? I would be happy to see it.

apache-spark apache-spark-sql
1 Answers

I am not sure but when i am running this sample select (SELECT uuid();) in query details i can see this

(2) Project [codegen id : 1]
Output [1]: [uuid(Some(-1736932742140897221)) AS uuid()#8]
Input: []

In Spark repo UUID expression is defined in misc.scala

  :
  usage = """_FUNC_() - Returns an universally unique identifier (UUID) string. The value is returned as a canonical UUID 36-character string.""",
  examples = """
    Examples:
      > SELECT _FUNC_();
       46707d92-02f4-4817-8116-a4c3b23e6266
  """,
  note = """
    The function is non-deterministic.
  """,
  since = "2.3.0",
  group = "misc_funcs")
  :

and is using RandomUUIDGenerator

...which provides further details about the algorithm:

  • For the algorithm, see RFC 4122: A Universally Unique IDentifier (UUID) URN Namespace, * section 4.4 "Algorithms for Creating a UUID from Truly Random or Pseudo-Random Numbers".
M_S0
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