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Warning:
CockroachDB v19.1 is no longer supported as of October 30, 2020. 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
.