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  1. MariaDB Server
  2. MDEV-27330

Wrong sorting order with DESC index and empty strings in MyISAM/Aria table

Details

    • Bug
    • Status: Closed (View Workflow)
    • Critical
    • Resolution: Fixed
    • N/A
    • 10.8.1
    • Server
    • None

    Description

      CREATE TABLE t (id int, c char(128) NOT NULL, KEY (c DESC)) ENGINE=MyISAM CHARSET latin1;
      		 
      INSERT INTO t VALUES (1,''),(2,'foo'),(3,''),(4,'bar');
      		 
       
      		 
      SELECT c FROM t ORDER BY c;
      		 
       
      		 
      # Cleanup
      		 
      DROP TABLE t;

      preview-10.8-MDEV-13756-desc-indexes 47c18283

      		 
      MariaDB [test]> SELECT c FROM t ORDER BY c;
      		 
      +-----+
      		 
      | c   |
      		 
      +-----+
      		 
      | bar |
      		 
      | foo |
      		 
      |     |
      		 
      |     |
      		 
      +-----+
      		 
      4 rows in set (0.000 sec)

      So, the empty strings go last, contrary to the expectation.
      Reproducible with MyISAM and Aria.
      Not reproducible with InnoDB.

      Attachments

        Issue Links

          is caused by

          Task - A task that needs to be done. MDEV-13756 Implement descending index: KEY (a DESC, b ASC)

          • Blocker - Blocks development and/or testing work, production could not run.
          • Closed
          relates to

          Bug - A problem which impairs or prevents the functions of the product. MDEV-27303 Table corruption after insert into a non-InnoDB table with DESC index

          • Blocker - Blocks development and/or testing work, production could not run.
          • Closed

          Activity

            Ascending order - Click to sort in descending order
            elenst Elena Stepanova created issue -
            elenst Elena Stepanova made changes -
            Field Original Value New Value
            serg Sergei Golubchik made changes -
            Status Open [ 1 ] In Progress [ 3 ]
            serg Sergei Golubchik made changes -
            serg Sergei Golubchik made changes -
            Status In Progress [ 3 ] Stalled [ 10000 ]
            serg Sergei Golubchik added a comment -

            pushed into preview-10.8-MDEV-13756-desc-indexes

            serg Sergei Golubchik added a comment - pushed into preview-10.8- MDEV-13756 -desc-indexes
            serg Sergei Golubchik made changes -
            Status Stalled [ 10000 ] In Testing [ 10301 ]
            serg Sergei Golubchik made changes -
            Fix Version/s 10.8.1 [ 26815 ]
            Fix Version/s 10.8 [ 26121 ]
            Resolution Fixed [ 1 ]
            Status In Testing [ 10301 ] Closed [ 6 ]

            People

              serg Sergei Golubchik
              elenst Elena Stepanova
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              Dates

                Created:
                Updated:
                Resolved:

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