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  1. Hive
  2. HIVE-1545

Add a bunch of UDFs and UDAFs



    • Type: New Feature
    • Status: Open
    • Priority: Minor
    • Resolution: Unresolved
    • Affects Version/s: None
    • Fix Version/s: None
    • Component/s: UDF
    • Labels:


      Here some UD(A)Fs which can be incorporated into the Hive distribution:

      UDFArgMax - Find the 0-indexed index of the largest argument. e.g., ARGMAX(4, 5, 3) returns 1.
      UDFBucket - Find the bucket in which the first argument belongs. e.g., BUCKET(x, b_1, b_2, b_3, ...), will return the smallest i such that x > b_


      but <= b_


      . Returns 0 if x is smaller than all the buckets.
      UDFFindInArray - Finds the 1-index of the first element in the array given as the second argument. Returns 0 if not found. Returns NULL if either argument is NULL. E.g., FIND_IN_ARRAY(5, array(1,2,5)) will return 3. FIND_IN_ARRAY(5, array(1,2,3)) will return 0.
      UDFGreatCircleDist - Finds the great circle distance (in km) between two lat/long coordinates (in degrees).
      UDFLDA - Performs LDA inference on a vector given fixed topics.
      UDFNumberRows - Number successive rows starting from 1. Counter resets to 1 whenever any of its parameters changes.
      UDFPmax - Finds the maximum of a set of columns. e.g., PMAX(4, 5, 3) returns 5.
      UDFRegexpExtractAll - Like REGEXP_EXTRACT except that it returns all matches in an array.
      UDFUnescape - Returns the string unescaped (using C/Java style unescaping).
      UDFWhich - Given a boolean array, return the indices which are TRUE.

      UDAFCollect - Takes all the values associated with a row and converts it into a list. Make sure to have: set hive.map.aggr = false;
      UDAFCollectMap - Like collect except that it takes tuples and generates a map.
      UDAFEntropy - Compute the entropy of a column.
      UDAFPearson (BROKEN!!!) - Computes the pearson correlation between two columns.
      UDAFTop - TOP(KEY, VAL) - returns the KEY associated with the largest value of VAL.
      UDAFTopN (BROKEN!!!) - Like TOP except returns a list of the keys associated with the N (passed as the third parameter) largest values of VAL.


        1. UDFTrim.java
          3 kB
          Jonathan Chang
        2. UDFStartsWith.java
          2 kB
          Jonathan Chang
        3. udfs.tar.gz
          7 kB
          Jonathan Chang
        4. udfs.tar.gz
          11 kB
          Jonathan Chang
        5. UDFRtrim.java
          3 kB
          Jonathan Chang
        6. UDFLtrim.java
          3 kB
          Jonathan Chang
        7. UDFFindInString.java
          2 kB
          Jonathan Chang
        8. UDFEndsWith.java
          2 kB
          Jonathan Chang
        9. ext.tar.gz
          19 kB
          Jonathan Chang
        10. core.tar.gz
          19 kB
          Jonathan Chang

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              • Assignee:
                jonchang Jonathan Chang
                jonchang Jonathan Chang
              • Votes:
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                21 Start watching this issue


                • Created: