Cluster By是用于将数据分桶的关键字,它会将数据按照指定的列进行分桶,并根据分桶键进行数据的分区。Cluster By可以提高查询性能,特别是在经常按照某个列进行查询或连接操作时,可以减少数据的扫描量。 示例代码片段: -- 创建表并使用 Cluster By 分桶CREATETABLEsales ( product STRING, amountINT) CLUSTEREDBY(pr...
## DDLCREATE TABLE bucket_tableA(user_id BIGINT, firstname STRING, lastname STRING)COMMENT 'A bucketed copy of user_info'PARTITIONED BY(ds STRING)CLUSTERED BY(user_id) INTO 31 BUCKETS;## DMLINSERT OVERWRITE bucket_tableA select * from xx; note: SPARK 对 HIVE 的桶表的支持尚不完善,具...
1 1.创建表的语句：Create [EXTERNAL] TABLE [IF NOT EXISTS] table_name[(col_name data_type [COMMENT col_comment], ...)][COMMENT table_comment][PARTITIONED BY (col_name data_type [COMMENT col_comment], ...)][CLUSTERED BY (col_name, col_name, ...) [SORTED BY (col_name [ASC|DES...
## DDLCREATETABLEbucket_tableA(user_idBIGINT, firstname STRING, lastname STRING)COMMENT'A bucketed copy of user_info'PARTITIONEDBY(ds STRING)CLUSTEREDBY(user_id)INTO31 BUCKETS;## DMLINSERTOVERWRITE bucket_tableAselect*fromxx; 1. 2. 3. 4. 5. 6. 7. INSERT OVERWRITE bucket_tableA SPARK...
对Hive(Inceptor)表分桶可以将表中记录按分桶键的哈希值分散进多个文件中，这些小文件称为桶。1. 创建分桶表 CREATE [EXTERNAL] TABLE table_name(col1 type [, col2 type ...])[PARTITIONED BY ...]CLUSTERED BY (...)[SORTED BY (...)]INTO num_buckets BUCKETS [ROW FORMAT row_format]...
cluster by 和 distribute by 是很相似的, 也采用HashPartition, 相当于他的升级版 最大的不同是, cluster by 里含有一个分桶的方法 create tableemp_buck(idint,namestring)clusteredby(id)into4buckets row format delimited fields terminated by'\t';...
1.Clustered By 对于每一个表(table)或者分区, Hive可以进一步组织成桶,也就是说桶是更为细粒度的数据范围划分。 Hive也是针对某一列进行桶的组织。Hive采用对列值哈希,然后除以桶的个数求余的方式决定该条记录存放在 哪个桶当中。 把表(或者分区)组织成桶(Bucket)有两个理由: ...
CREATE TABLE bucket_tableA(user_id BIGINT, firstname STRING, lastname STRING) COMMENT 'A bucketed copy of user_info' PARTITIONED BY(ds STRING) CLUSTERED BY(user_id) INTO 31 BUCKETS; ## DML INSERT OVERWRITE bucket_tableA select * from xx; ...
create table xxxxxx_uid_online_buck( `datehour` string, `halfhourtype` string, `uid` string, `roomid` string, `roomcreatoruid` string, `staytime` string) clustered by(uid) sorted by(uid ASC) into 4 buckets row format delimited
4、分桶结构表:CLUSTERED BY 4.1应用场景 4.2分桶表构建 4.3本质 5、分桶与分区的关联 ==分桶与分区有什么区别?== 分区与分桶能不能放在一起? 0、表的创建语句 CREATE [EXTERNAL] TABLE [IF NOT EXISTS] [db_name.]table_name ( col1 typ1, ...