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  1. Hive
  2. HIVE-5506

Hive SPLIT function does not return array correctly

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: 0.9.0, 0.10.0, 0.11.0
    • Fix Version/s: 0.13.0
    • Component/s: SQL, UDF
    • Labels:
      None
    • Environment:

      Hive

    • Tags:
      HIVE SPLIT UDF

      Description

      Hello all, I think I have outlined a bug in the hive split function:

      Summary: When calling split on a string of data, it will only return all array items if the the last array item has a value. For example, if I have a string of text delimited by tab with 7 columns, and the first four are filled, but the last three are blank, split will only return a 4 position array. If any number of "middle" columns are empty, but the last item still has a value, then it will return the proper number of columns. This was tested in Hive 0.9 and hive 0.11.

      Data:
      (Note \t represents a tab char, \x09 the line endings should be \n (UNIX style) not sure what email will do to them). Basically my data is 7 lines of data with the first 7 letters separated by tab. On some lines I've left out certain letters, but kept the number of tabs exactly the same.

      input.txt
      a\tb\tc\td\te\tf\tg
      a\tb\tc\td\te\t\tg
      a\tb\t\td\t\tf\tg
      \t\t\td\te\tf\tg
      a\tb\tc\td\t\t\t
      a\t\t\t\te\tf\tg
      a\t\t\td\t\t\tg

      I then created a table with one column from that data:

      DROP TABLE tmp_jo_tab_test;
      CREATE table tmp_jo_tab_test (message_line STRING)
      STORED AS TEXTFILE;

      LOAD DATA LOCAL INPATH '/tmp/input.txt'
      OVERWRITE INTO TABLE tmp_jo_tab_test;

      Ok just to validate I created a python counting script:

      #!/usr/bin/python

      import sys

      for line in sys.stdin:
      line = line[0:-1]
      out = line.split("\t")
      print len(out)

      The output there is :
      $ cat input.txt |./cnt_tabs.py
      7
      7
      7
      7
      7
      7
      7

      Based on that information, split on tab should return me 7 for each line as well:

      hive -e "select size(split(message_line, '
      t')) from tmp_jo_tab_test;"

      7
      7
      7
      7
      4
      7
      7

      However it does not. It would appear that the line where only the first four letters are filled in(and blank is passed in on the last three) only returns 4 splits, where there should technically be 7, 4 for letters included, and three blanks.

      a\tb\tc\td\t\t\t

        Attachments

        1. HIVE-5506.1.patch
          3 kB
          Vikram Dixit K
        2. HIVE-5506.2.patch
          3 kB
          Vikram Dixit K

          Activity

            People

            • Assignee:
              vikram.dixit Vikram Dixit K
              Reporter:
              mandoskippy John Omernik
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              Dates

              • Created:
                Updated:
                Resolved: