[MDEV-25351] SHOW INDEX cardinality and COUNT(DISTINCT primary key) differ Created: 2021-04-06 Updated: 2023-06-26 Resolved: 2023-06-26 |
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| Status: | Closed |
| Project: | MariaDB Server |
| Component/s: | None |
| Affects Version/s: | 10.2.27 |
| Fix Version/s: | N/A |
| Type: | Bug | Priority: | Critical |
| Reporter: | Rob Schwyzer | Assignee: | Sergei Petrunia |
| Resolution: | Incomplete | Votes: | 0 |
| Labels: | None | ||
| Environment: |
CentOS |
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| Description |
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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? |