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  1. MariaDB Server
  2. MDEV-21032

Index causes incorrect result when comparing float-point number with INT

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Details

    • Bug
    • Status: Confirmed (View Workflow)
    • Major
    • Resolution: Unresolved
    • 5.5, 10.0, 10.1, 10.4.11, 10.2, 10.3, 10.4
    • 10.4
    • None
    • None
    • Ubuntu 19.04

    Description

      Hi everyone,

      On the latest trunk version (0308de9), I could observe a bug, as demonstrated by the following test case:

      CREATE TABLE t0(c0 INT);
      INSERT INTO t0 VALUES (1);
      CREATE INDEX i0 ON t0(c0);
      SELECT * FROM t0 WHERE 0.5 = c0; -- unexpected: row is fetched
      

      Only when the index is created does MariaDB compute an incorrect result set, containing the row. As demonstrated below, the expression should evaluate to FALSE:

      SELECT 0.5 = c0 FROM t0; -- evaluates to FALSE
      

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            bar Alexander Barkov
            mrigger Manuel Rigger
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            Dates

              Created:
              Updated:

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