hbase - 如何将 Hive 表与 HBase 表映射？

Question

我创建了一个 HBase 表，如下所示:

create 'nancy', 'cf'

并在 Hive 中创建了一个表，如下所示:

create external table nancy( id int, name string)

stored by 'org.apache.hadoop.hive.hbase.HBaseStorageHandler'

WITH SERDEPROPERTIES ("hbase.columns.mapping" = ":key, cf:name")

TBLPROPERTIES("hbase.table.name"="nancy");

我在映射它写吗？ “hbase.columns.mapping”中的Key是什么意思？
谁能解释一下这个映射？

Answer 1

您是否面临任何特定问题？查询对我来说很好。

key 表示您正在使用此字段作为表键。记住 hive 表中的每个字段都可以映射到以下字段之一:

表键(使用 :key 作为选择器)

列族 (cf:)(Hive 中的 MAP 字段

栏目

回复您的意见:

hive> CREATE EXTERNAL TABLE hbase_table_2(key int, name string)

    > STORED BY 'org.apache.hadoop.hive.hbase.HBaseStorageHandler'
    > WITH SERDEPROPERTIES ("hbase.columns.mapping" = ":key,cf:name")
    > TBLPROPERTIES("hbase.table.name" = "nancy");
OK
Time taken: 5.106 seconds

hive> select * from hbase_table_2;
OK
Time taken: 0.077 seconds

hive> INSERT OVERWRITE TABLE hbase_table_2 SELECT * FROM demo WHERE id=1;
Total MapReduce jobs = 1
Launching Job 1 out of 1
Number of reduce tasks is set to 0 since there's no reduce operator
Starting Job = job_201308011237_0003, Tracking URL = http://localhost:50030/jobdetails.jsp?jobid=job_201308011237_0003
Kill Command = /Users/miqbal1/hadoop-eco/hadoop-1.1.2/libexec/../bin/hadoop job  -kill job_201308011237_0003
Hadoop job information for Stage-0: number of mappers: 1; number of reducers: 0
2013-08-01 16:29:21,832 Stage-0 map = 0%,  reduce = 0%
2013-08-01 16:29:23,843 Stage-0 map = 100%,  reduce = 0%
2013-08-01 16:29:24,849 Stage-0 map = 100%,  reduce = 100%
Ended Job = job_201308011237_0003
1 Rows loaded to hbase_table_2
MapReduce Jobs Launched: 
Job 0: Map: 1   HDFS Read: 256 HDFS Write: 0 SUCCESS
Total MapReduce CPU Time Spent: 0 msec
OK
Time taken: 8.392 seconds
hive> 

这是我的 HBase 表:

hbase(main):017:0> scan 'nancy'
ROW                                      COLUMN+CELL                                                                                                          
 1                                       column=cf:name, timestamp=1375354762803, value=tariq                                                                 
1 row(s) in 0.0300 seconds