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  1. MariaDB Server
  2. MDEV-6971

Bad results with joins comparing TIME and DOUBLE/DECIMAL columns

Details

    • Bug
    • Status: Closed (View Workflow)
    • Major
    • Resolution: Fixed
    • 5.5.40, 10.0.14
    • 10.0.15
    • Optimizer
    • None

    Description

      DROP TABLE IF EXISTS t1,t2;
      		 
      CREATE TABLE t1 (a TIME(6) PRIMARY KEY);
      		 
      INSERT INTO t1 VALUES ('10:20:30');
      		 
      DROP TABLE IF EXISTS t2;
      		 
      CREATE TABLE t2 (a DOUBLE);
      		 
      INSERT INTO t2 VALUES (102030),(102030.000000001);
      		 
      SELECT t1.* FROM t1 JOIN t2 USING(a);
      		 
      SELECT t1.* FROM t1 LEFT JOIN t2 USING(a);

      Both SELECT queries correctly return 2 rows.

      If I add a primary key on t2 and return the same queries:

      ALTER TABLE t2 ADD PRIMARY KEY(a);
      		 
      SELECT t1.* FROM t1 JOIN t2 USING(a);
      		 
      SELECT t1.* FROM t1 LEFT JOIN t2 USING(a);

      both SELECT queries return only one row.
      This is wrong. Two rows are expected for both queries.

      The same problem is repeatable if I change t2.a from DOUBLE to DECIMAL(30,10).

      Attachments

        Activity

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          bar Alexander Barkov created issue -
          bar Alexander Barkov made changes -
          Field Original Value New Value
          Summary Bad results with joins comparing TIME and DOUBLE columns Bad results with joins comparing TIME and DOUBLE/DECIMAL columns
          bar Alexander Barkov made changes -
          Description {code}
          DROP TABLE IF EXISTS t1,t2;
          CREATE TABLE t1 (a TIME(6) PRIMARY KEY);
          INSERT INTO t1 VALUES ('10:20:30');
          DROP TABLE IF EXISTS t2;
          CREATE TABLE t2 (a DOUBLE);
          INSERT INTO t2 VALUES (102030),(102030.000000001);
          SELECT t1.* FROM t1 JOIN t2 USING(a);
          SELECT t1.* FROM t1 LEFT JOIN t2 USING(a);
          {code}
          Both SELECT queries correctly return 2 rows.

          If I add a primary key on t2 and return the same queries:
          {code:sql}
          ALTER TABLE t2 ADD PRIMARY KEY(a);
          SELECT t1.* FROM t1 JOIN t2 USING(a);
          SELECT t1.* FROM t1 LEFT JOIN t2 USING(a);
          {code}
          both SELECT queries return only one row.
          This is wrong. Two rows are expected for both queries.
          		 {code}
          DROP TABLE IF EXISTS t1,t2;
          CREATE TABLE t1 (a TIME(6) PRIMARY KEY);
          INSERT INTO t1 VALUES ('10:20:30');
          DROP TABLE IF EXISTS t2;
          CREATE TABLE t2 (a DOUBLE);
          INSERT INTO t2 VALUES (102030),(102030.000000001);
          SELECT t1.* FROM t1 JOIN t2 USING(a);
          SELECT t1.* FROM t1 LEFT JOIN t2 USING(a);
          {code}
          Both SELECT queries correctly return 2 rows.

          If I add a primary key on t2 and return the same queries:
          {code:sql}
          ALTER TABLE t2 ADD PRIMARY KEY(a);
          SELECT t1.* FROM t1 JOIN t2 USING(a);
          SELECT t1.* FROM t1 LEFT JOIN t2 USING(a);
          {code}
          both SELECT queries return only one row.
          This is wrong. Two rows are expected for both queries.

          The same problem is repeatable if I change t2.a from DOUBLE to DECIMAL(30,10).
          serg Sergei Golubchik made changes -
          Fix Version/s 10.0 [ 16000 ]
          bar Alexander Barkov made changes -
          Component/s Optimizer [ 10200 ]
          Fix Version/s 10.0.15 [ 17300 ]
          Fix Version/s 10.0 [ 16000 ]
          Resolution Fixed [ 1 ]
          Status Open [ 1 ] Closed [ 6 ]
          ratzpo Rasmus Johansson (Inactive) made changes -
          Workflow MariaDB v2 [ 57002 ] MariaDB v3 [ 64900 ]
          serg Sergei Golubchik made changes -
          Workflow MariaDB v3 [ 64900 ] MariaDB v4 [ 148373 ]

          People

            bar Alexander Barkov
            bar Alexander Barkov
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            Dates

              Created:
              Updated:
              Resolved:

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