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  1. MariaDB Server
  2. MDEV-25351

SHOW INDEX cardinality and COUNT(DISTINCT primary key) differ

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Details

    • Bug
    • Status: Closed (View Workflow)
    • Critical
    • Resolution: Incomplete
    • 10.2.27
    • N/A
    • None
    • None
    • CentOS

    Description

      User has a table with of type ENGINE=InnoDB DEFAULT CHARSET=utf8 with a primary key defined as char(32) NOT NULL DEFAULT '',.

      When using SELECT COUNT(DISTINCT primarykey, the user gets 92259134. However, SHOW INDEX's cardinality returns 6853710. This occurs regardless of whether innodb_stats_auto_recalc is on or off and persists through ANALYZE TABLE ... PERSISTENT FOR ALL.

      Will this pose problems for the optimizer? Is there a way to address this if it will?

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            psergei Sergei Petrunia
            rob.schwyzer@mariadb.com Rob Schwyzer (Inactive)
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            Dates

              Created:
              Updated:
              Resolved:

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