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SHOW STATS_BUCKETS

SHOW STATS_BUCKETS 语句显示 统计信息 中的桶信息。

目前,SHOW STATS_BUCKETS 语句返回以下列:

列名描述
Db_name数据库名称
Table_name表名称
Partition_name分区名称
Column_name列名称(当 is_index 为 0 时)或索引名称(当 is_index 为 1 时)
Is_index是否为索引列
Bucket_id桶的 ID
Count落在该桶及之前桶中的所有值的数量
Repeats最大值的出现次数
Lower_bound最小值
Upper_bound最大值
Ndv桶中不同值的数量。该字段已废弃,由于其不准确,始终显示 0。

概要

ShowStatsBucketsStmt
SHOW STATS_BUCKETS ShowLikeOrWhere
ShowLikeOrWhere
LIKE SimpleExpr WHERE Expression

示例

SHOW STATS_BUCKETS WHERE Table_name='t';
+---------+------------+----------------+-------------+----------+-----------+-------+---------+--------------------------+--------------------------+------+
| Db_name | Table_name | Partition_name | Column_name | Is_index | Bucket_id | Count | Repeats | Lower_Bound              | Upper_Bound              | Ndv  |
+---------+------------+----------------+-------------+----------+-----------+-------+---------+--------------------------+--------------------------+------+
| test    | t          |                | a           |        0 |         0 |     1 |       1 | 2023-12-27 00:00:00      | 2023-12-27 00:00:00      |    0 |
| test    | t          |                | a           |        0 |         1 |     2 |       1 | 2023-12-28 00:00:00      | 2023-12-28 00:00:00      |    0 |
| test    | t          |                | ia          |        1 |         0 |     1 |       1 | (NULL, 2)                | (NULL, 2)                |    0 |
| test    | t          |                | ia          |        1 |         1 |     2 |       1 | (NULL, 4)                | (NULL, 4)                |    0 |
| test    | t          |                | ia          |        1 |         2 |     3 |       1 | (2023-12-27 00:00:00, 1) | (2023-12-27 00:00:00, 1) |    0 |
| test    | t          |                | ia          |        1 |         3 |     4 |       1 | (2023-12-28 00:00:00, 3) | (2023-12-28 00:00:00, 3) |    0 |
+---------+------------+----------------+-------------+----------+-----------+-------+---------+--------------------------+--------------------------+------+
6 行结果(0.00 秒)

MySQL 兼容性

该语句是 TiDB 对 MySQL 语法的扩展。

相关链接