The SHOW STATISTICS statement lists table statistics used by the cost-based optimizer.

Synopsis

SHOW STATISTICS FOR TABLE table_name

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

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> CREATE STATISTICS students ON id FROM students_by_list;
CREATE STATISTICS
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> 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:

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> 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:

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> 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.

See Also



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