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  1. MariaDB Server
  2. MDEV-22923

Data Truncation when using UNION SELECT

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    Details

    • Type: Bug
    • Status: Open (View Workflow)
    • Priority: Major
    • Resolution: Unresolved
    • Affects Version/s: 10.3.23, 10.4.13
    • Fix Version/s: 10.3, 10.4, 10.5
    • Component/s: Data types
    • Labels:
      None
    • Environment:
      Linux

      Description

      This issue is a little bit similar to MDEV-17226

      When selecting a large number of string characters witih an UNION the data gets truncated.
      I did not found any variable which can change this behaviour and I did not get any answers on my stackoverflow question regarding this:
      https://stackoverflow.com/questions/62404168/mariadb-cuts-of-text-when-select-with-union

      Example is attached.
      Simple example:
      SELECT 'LARGETEXT' works fine.
      SELECT 'SHORTTEXT' UNION SELECT 'LARGETEXT' truncated the text after about 34797 Bytes.
      The order of the columns does not make any difference. So also
      SELECT 'LARGETEXT' UNION SELECT 'SHORTTEXT'
      does fail.

      This seems to be critical for me because the user is not noticed about loss of data.

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              Assignee:
              bar Alexander Barkov
              Reporter:
              ThomasChr Thomas Christlieb
              Votes:
              4 Vote for this issue
              Watchers:
              6 Start watching this issue

                Dates

                Created:
                Updated: