SQL Function

可透過對Hive 下一些 SQL function

https://cwiki.apache.org/confluence/display/Hive/LanguageManual+UDF

去對HBase做一些計算例如AVG()

ex: 

hive>  select AVG(times) from hivetableerr;

[Result]

Hadoop job information for Stage-1: number of mappers: 1; number of reducers: 1

2014-10-16 15:45:47,503 Stage-1 map = 0%,  reduce = 0%

2014-10-16 15:46:05,165 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 2.19 sec

2014-10-16 15:46:19,847 Stage-1 map = 100%,  reduce = 100%, Cumulative CPU 3.49 sec

MapReduce Total cumulative CPU time: 3 seconds 490 msec

Ended Job = job_1412160247541_0074

MapReduce Jobs Launched:

Job 0: Map: 1  Reduce: 1   Cumulative CPU: 3.49 sec   HDFS Read: 255 HDFS Write: 5 SUCCESS

Total MapReduce CPU Time Spent: 3 seconds 490 msec

OK

47.0

Time taken: 44.88 seconds, Fetched: 1 row(s)