Doris分区

1、创建分区表

（1）默认分区

当不使用 Partition 建表时，系统会自动生成一个和表名同名的，全值范围的 Partition。该 Partition 对用户不可见，并且不可删改。

CREATE TABLE table1 (
     siteid INT DEFAULT '10',
     citycode SMALLINT,
     username VARCHAR(32) DEFAULT '',     
     pv BIGINT SUM DEFAULT '0' 
) 
AGGREGATE KEY(siteid, citycode, username) 
DISTRIBUTED BY HASH(siteid) BUCKETS 10 
PROPERTIES("replication_num" = "1")

（2）指定多分区
下面建表语句指定了三个分区，Partition 支持通过 VALUES LESS THAN (…) 仅指定上界，系统会将前一个分区的上界作为该分区的下界。

CREATE TABLE table2 (
     event_day DATE,     
     siteid INT DEFAULT '10',     
     citycode SMALLINT,     
     username VARCHAR(32) DEFAULT '',     
     pv BIGINT SUM DEFAULT '0' 
) 
AGGREGATE KEY(event_day, siteid, citycode, username) 
PARTITION BY RANGE(event_day) (     
	PARTITION p201706 VALUES LESS THAN ('2017-07-01'),     
	PARTITION p201707 VALUES LESS THAN ('2017-08-01'),     
	PARTITION p201708 VALUES LESS THAN ('2017-09-01') 
) 
DISTRIBUTED BY HASH(siteid) BUCKETS 10 
PROPERTIES("replication_num" = "2")

3、查看分区信息

MySQL [test]> show partitions from test.table1 \G
*************************** 1. row ***************************
             PartitionId: 10006
           PartitionName: table1
          VisibleVersion: 2
      VisibleVersionTime: 2021-08-30 13:46:04
      VisibleVersionHash: 6956565961900736218
                   State: NORMAL
            PartitionKey: 
                   Range: 
         DistributionKey: siteid
                 Buckets: 10
          ReplicationNum: 2
           StorageMedium: HDD
            CooldownTime: 9999-12-31 23:59:59
LastConsistencyCheckTime: 2021-08-30 23:00:54
                DataSize: 6.736 KB
              IsInMemory: false
1 row in set (0.01 sec)

MySQL [test]> show partitions from test.table2 \G
*************************** 1. row ***************************
             PartitionId: 10152
           PartitionName: p201706
          VisibleVersion: 1
      VisibleVersionTime: 2021-08-30 15:00:38
      VisibleVersionHash: 0
                   State: NORMAL
            PartitionKey: event_day
                   Range: [types: [DATE]; keys: [0000-01-01]; ..types: [DATE]; keys: [2017-07-01]; )
         DistributionKey: siteid
                 Buckets: 10
          ReplicationNum: 2
           StorageMedium: HDD
            CooldownTime: 9999-12-31 23:59:59
LastConsistencyCheckTime: NULL
                DataSize: .000 
              IsInMemory: false
*************************** 2. row ***************************
             PartitionId: 10153
           PartitionName: p201707
          VisibleVersion: 2
      VisibleVersionTime: 2021-08-30 15:07:45
      VisibleVersionHash: 8754137926813451799
                   State: NORMAL
            PartitionKey: event_day
                   Range: [types: [DATE]; keys: [2017-07-01]; ..types: [DATE]; keys: [2017-08-01]; )
         DistributionKey: siteid
                 Buckets: 10
          ReplicationNum: 2
           StorageMedium: HDD
            CooldownTime: 9999-12-31 23:59:59
LastConsistencyCheckTime: 2021-08-30 23:00:54
                DataSize: 8.633 KB
              IsInMemory: false
*************************** 3. row ***************************
             PartitionId: 10154
           PartitionName: p201708
          VisibleVersion: 1
      VisibleVersionTime: 2021-08-30 15:00:38
      VisibleVersionHash: 0
                   State: NORMAL
            PartitionKey: event_day
                   Range: [types: [DATE]; keys: [2017-08-01]; ..types: [DATE]; keys: [2017-09-01]; )
         DistributionKey: siteid
                 Buckets: 10
          ReplicationNum: 2
           StorageMedium: HDD
            CooldownTime: 9999-12-31 23:59:59
LastConsistencyCheckTime: NULL
                DataSize: .000 
              IsInMemory: false
3 rows in set (0.00 sec)

MySQL [test]>