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Warning:
As of October 30, 2020, CockroachDB v19.1 is no longer supported. For more details, refer to the Release Support Policy.
The SHOW STATISTICS
statement lists table statistics used by the cost-based optimizer.
Synopsis
Required Privileges
No privileges are required to list table statistics.
Parameters
Parameter | Description |
---|---|
table_name |
The name of the table you want to view statistics for. |
Examples
List table statistics
> CREATE STATISTICS students ON id FROM students_by_list;
CREATE STATISTICS
> SHOW STATISTICS FOR TABLE students_by_list;
statistics_name | column_names | created | row_count | distinct_count | null_count | histogram_id
+-----------------+--------------+----------------------------------+-----------+----------------+------------+--------------+
students | {"id"} | 2018-10-26 15:06:34.320165+00:00 | 0 | 0 | 0 | NULL
(1 row)
Delete statistics
To delete statistics for all tables in all databases:
> DELETE FROM system.table_statistics WHERE true;
To delete a named set of statistics (e.g, one named "my_stats"), run a query like the following:
> DELETE FROM system.table_statistics WHERE name = 'my_stats';
After deleting statistics, restart the nodes in your cluster to clear the statistics caches.
For more information about the DELETE
statement, see DELETE
.