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  1. MariaDB Server
  2. MDEV-2231

LP:729067 - Wrong result with STRAIGHT_JOIN + OR + IN subquery in maria-5.3, maria-5.3-mwl89

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Details

    • Bug
    • Status: Closed (View Workflow)
    • Critical
    • Resolution: Fixed
    • None
    • None
    • None

    Description

      Reproducible in maria-5.3, maria-5.3-mwl89 regardless of switch. Not reproducible in maria-5.2, mysql-5.5

      The following query:

      SELECT STRAIGHT_JOIN *
      FROM t1
      JOIN t2 ON t2.f2 = t1.f1
      WHERE ( t1.f1 ) IN ( SELECT f1 FROM t1 )
      AND t1.f1 = t2.f1
      OR t1.f1 = 9;

      returns no rows even though there is one row for which t2.f2 = t1.f1 and t1.f1 = 9 is TRUE , hence the entire WHERE clause is true.

      I was unable to remove STRAIGHT_JOIN even if I rotated the places of t1 and t2.

      EXPLAIN:

      id select_type table type possible_keys key key_len ref rows Extra
      1 PRIMARY t1 ALL PRIMARY NULL NULL NULL 2 Using where
      1 PRIMARY t2 ALL PRIMARY NULL NULL NULL 2 Range checked for each record (index map: 0x1)
      2 DEPENDENT SUBQUERY t1 unique_subquery PRIMARY PRIMARY 4 func 1 Using index

      test case:

      CREATE TABLE t1 ( f1 int, f2 int, PRIMARY KEY (f1)) ;
      INSERT IGNORE INTO t1 VALUES ('9','4'),('10','9');

      CREATE TABLE t2 ( f1 int, f2 int, PRIMARY KEY (f1)) ;
      INSERT IGNORE INTO t2 VALUES ('9','4'),('10','9');

      SELECT STRAIGHT_JOIN *
      FROM t1
      JOIN t2 ON t2.f2 = t1.f1
      WHERE ( t1.f1 ) IN ( SELECT f1 FROM t1 )
      AND t1.f1 = t2.f1
      OR t1.f1 = 9;

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            igor Igor Babaev (Inactive)
            philipstoev Philip Stoev (Inactive)
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            Dates

              Created:
              Updated:
              Resolved:

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