声明桶表时,需要指定分桶字段和桶的个数(CLUSTERED BY(user_id) INTO 31 BUCKETS); 桶表的写入操作,在底层执行时,会自动添加 CLUSTER BY 子语句 以按桶表声明时指定的分桶字段来分布数据;(如果是 0.x 或 1.x 的 HIVE 版本,需要配置参数 set hive.enforce.bucketing = true; HIVE 2.
声明桶表时,需要指定分桶字段和桶的个数(CLUSTERED BY(user_id) INTO 31 BUCKETS); 桶表的写入操作,在底层执行时,会自动添加 CLUSTER BY 子语句 以按桶表声明时指定的分桶字段来分布数据;(如果是 0.x 或 1.x 的 HIVE 版本,需要配置参数 set hive.enforce.bucketing = true; HIVE 2.X 后,该参数被re...
In the example above, the table is clustered by a hash function of userid into 32 buckets. Within each bucket the data is sorted in increasing order of viewTime. Such an organization allows the user to do efficient sampling on the clustered column - in this case userid. The sorting prope...
The sampling clause allows the users to write queries for samples of the data instead of the whole table. Currently the sampling is done on the columns that are specified in the CLUSTERED BY clause of the CREATE TABLE statement. In the following example we choose 3rd bucket out of the 32 ...
partitionedBy Partition column description, which is used to partition tables. The columns parameter is used to list the column name, type, and optional remarks. clusteredBy Bucket column description, including the columnNames, sortedBy, and numberOfBuckets parameters. The columnNames parameter includ...
clusteredBy Bucket column description, including the columnNames, sortedBy, and numberOfBuckets parameters. The columnNames parameter includes columnName and sorting sequence (ASC for ascending or DESC for descending). format Storage format description including parameters for rowFormat, storedAs, and st...
PARTITIONED BY(dt STRING, country STRING) CLUSTERED BY(userid) SORTED BY(viewTime) INTO 32 BUCKETS ROW FORMAT DELIMITED FIELDS TERMINATED BY '1' COLLECTION ITEMS TERMINATED BY '2' MAP KEYS TERMINATED BY '3' STORED AS SEQUENCEFILE; In the example above, the table is clustered by a hash fu...
clusteredBy Bucket column description, including the columnNames, sortedBy, and numberOfBuckets parameters. The columnNames parameter includes columnName and sorting sequence (ASC indicates an ascending order, and DESC indicates a descending order). format Storage format. The parameters include rowFormat...