|NO.Z.00031|——————————|BigDataEnd|——|Hadoop&OLAP_ClickHouse.V03|——|ClickHouse.v03|ClickHouse语法|分区表|

一、分区表：

### --- 分区表

~~~     只有合并数（MergeTree）家族的表引擎支持分区表
~~~     可以利用分区表，做定位查询，缩小查询范围。
~~~     分区字段不易设的太小

### --- 分区表案例：

~~~     # 创建分区表
hadoop01 :) CREATE TABLE partition_v1 (
            `ID` String,
            `URL` String,
            `EventTime` Date
            ) ENGINE = MergeTree()
            PARTITION BY toYYYYMM(EventTime)
            ORDER BY ID;

~~~     # 加载数据

hadoop01 :) insert into partition_v1 values (
            'A000',
            'www.baidu.com',
            '2021-10-01'),
            ('A001','www.sina.com',
            '2021-11-01');

~~~     # 查询数据

hadoop01 :) select table,
            partition,
            path from system.parts 
            where table = 'partition_v1';
~~~输出参数
┌─table────────┬─partition─┬─path────────────────────────────────────────────────────────┐
│ partition_v1 │ 202110    │ /var/lib/clickhouse/data/default/partition_v1/202110_1_1_0/ │
│ partition_v1 │ 202111    │ /var/lib/clickhouse/data/default/partition_v1/202111_2_2_0/ │
└──────────────┴───────────┴─────────────────────────────────────────────────────────────┘

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Walter Savage Landor:strove with none,for none was worth my strife.Nature I loved and, next to Nature, Art:I warm'd both hands before the fire of life.It sinks, and I am ready to depart

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