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  1. MariaDB Server
  2. MDEV-16134

Wrong I_S.COLUMNS.CHARACTER_XXX_LENGTH value for compressed columns

Details

    • Bug
    • Status: Closed (View Workflow)
    • Major
    • Resolution: Fixed
    • 10.3(EOL)
    • 10.3.7
    • Data types
    • None

    Description

      This script queries I_S for a latin1 compressed varchar column:

      CREATE OR REPLACE TABLE t1 (a VARCHAR(10) CHARACTER SET latin1 COMPRESSED);
      		 
      SELECT
      		 
        CHARACTER_MAXIMUM_LENGTH, CHARACTER_OCTET_LENGTH
      		 
      FROM
      		 
        INFORMATION_SCHEMA.COLUMNS
      		 
      WHERE
      		 
        TABLE_SCHEMA='test' AND TABLE_NAME='t1' AND COLUMN_NAME='a';


      +--------------------------+------------------------+
      		 
      | CHARACTER_MAXIMUM_LENGTH | CHARACTER_OCTET_LENGTH |
      		 
      +--------------------------+------------------------+
      		 
      |                       11 |                     11 |
      		 
      +--------------------------+------------------------+

      11 looks wrong. The expected value would be 10 for both columns.

      Now trying an utf8 column:

      CREATE OR REPLACE TABLE t1 (a VARCHAR(10) CHARACTER SET utf8 COMPRESSED);
      		 
      SELECT
      		 
        CHARACTER_MAXIMUM_LENGTH, CHARACTER_OCTET_LENGTH
      		 
      FROM
      		 
        INFORMATION_SCHEMA.COLUMNS
      		 
      WHERE
      		 
        TABLE_SCHEMA='test' AND TABLE_NAME='t1' AND COLUMN_NAME='a';


      +--------------------------+------------------------+
      		 
      | CHARACTER_MAXIMUM_LENGTH | CHARACTER_OCTET_LENGTH |
      		 
      +--------------------------+------------------------+
      		 
      |                       10 |                     31 |
      		 
      +--------------------------+------------------------+

      The value for CHARACTER_OCTET_LENGTH is wrong. The expected result is 30.

      Attachments

        Issue Links

          relates to

          Bug - A problem which impairs or prevents the functions of the product. MDEV-15592 Column COMPRESSED should select a 'high order' datatype

          • Major - Major loss of function.
          • Closed

          Activity

            Transition Time In Source Status Execution Times
            Alexander Barkov made transition -
            Open In Progress
            		4h 14m 1
            Alexander Barkov made transition -
            In Progress In Review
            		5s 1
            Sergey Vojtovich made transition -
            In Review Stalled
            		7m 2s 1
            Alexander Barkov made transition -
            Stalled Closed
            		1m 48s 1

            People

              bar Alexander Barkov
              bar Alexander Barkov
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              Dates

                Created:
                Updated:
                Resolved:

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