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sql-statement-show-table-distribution.md

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SHOW TABLE DISTRIBUTION
介绍 TiDB 数据库中 SHOW TABLE DISTRIBUTION 的使用概况。

SHOW TABLE DISTRIBUTION 从 v8.5.4 和 v9.0.0 开始引入

SHOW TABLE DISTRIBUTION 语句用于显示指定表的 Region 分布情况。

语法图

ShowTableDistributionStmt ::=
    "SHOW" "TABLE" TableName "DISTRIBUTIONS"

TableName ::=
    (SchemaName ".")? Identifier

示例

显示当前表 t 的 Region 分布情况：

CREATE TABLE `t` (
  `a` int DEFAULT NULL,
  `b` int DEFAULT NULL,
  KEY `idx` (`b`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin 
PARTITION BY RANGE (`a`)
(PARTITION `p1` VALUES LESS THAN (10000),
 PARTITION `p2` VALUES LESS THAN (MAXVALUE));
SHOW TABLE t DISTRIBUTIONS;
+----------------+----------+------------+---------------------+-------------------+--------------------+-------------------+--------------------+--------------------------+-------------------------+--------------------------+------------------------+-----------------------+------------------------+
| PARTITION_NAME | STORE_ID | STORE_TYPE | REGION_LEADER_COUNT | REGION_PEER_COUNT | REGION_WRITE_BYTES | REGION_WRITE_KEYS | REGION_WRITE_QUERY | REGION_LEADER_READ_BYTES | REGION_LEADER_READ_KEYS | REGION_LEADER_READ_QUERY | REGION_PEER_READ_BYTES | REGION_PEER_READ_KEYS | REGION_PEER_READ_QUERY |
+----------------+----------+------------+---------------------+-------------------+--------------------+-------------------+--------------------+--------------------------+-------------------------+--------------------------+------------------------+-----------------------+------------------------+
| p1             |        1 | tikv       |                   0 |                 0 |                  0 |                 0 |                  0 |                        0 |                       0 |                        0 |                      0 |                     0 |                      0 |
| p1             |       15 | tikv       |                   0 |                 0 |                  0 |                 0 |                  0 |                        0 |                       0 |                        0 |                      0 |                     0 |                      0 |
| p1             |        4 | tikv       |                   1 |                 1 |                  0 |                 0 |                  0 |                        0 |                       0 |                        0 |                      0 |                     0 |                      0 |
| p1             |        5 | tikv       |                   0 |                 1 |                  0 |                 0 |                  0 |                        0 |                       0 |                        0 |                      0 |                     0 |                      0 |
| p1             |        6 | tikv       |                   0 |                 1 |                  0 |                 0 |                  0 |                        0 |                       0 |                        0 |                      0 |                     0 |                      0 |
| p2             |        1 | tikv       |                   0 |                 0 |                  0 |                 0 |                  0 |                        0 |                       0 |                        0 |                      0 |                     0 |                      0 |
| p2             |       15 | tikv       |                   0 |                 0 |                  0 |                 0 |                  0 |                        0 |                       0 |                        0 |                      0 |                     0 |                      0 |
| p2             |        4 | tikv       |                   0 |                 1 |                  0 |                 0 |                  0 |                        0 |                       0 |                        0 |                      0 |                     0 |                      0 |
| p2             |        5 | tikv       |                   1 |                 1 |                  0 |                 0 |                  0 |                        0 |                       0 |                        0 |                      0 |                     0 |                      0 |
| p2             |        6 | tikv       |                   0 |                 1 |                  0 |                 0 |                  0 |                        0 |                       0 |                        0 |                      0 |                     0 |                      0 |
+----------------+----------+------------+---------------------+-------------------+--------------------+-------------------+--------------------+--------------------------+-------------------------+--------------------------+------------------------+-----------------------+------------------------+

MySQL 兼容性

该语句是 TiDB 对 MySQL 语法的扩展。

另请参阅