Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Threaded View
Hive, mail # user - Re: Difference between like %A% and %a%


Copy link to this message
-
Re: Difference between like %A% and %a%
Sai Sai 2013-05-24, 10:59


Just wondering about this, please let me know if you have any suggestions why we r getting these results:

This  query does not return any data:

Query1:hive (test)> select full_name from states where abbreviation like '%a%';
But this query returns data successfully:

Query2:hive (test)> select full_name from states where abbreviation like '%A%';

Result of Query 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_201305240156_0012, Tracking URL = http://ubuntu:50030/jobdetails.jsp?jobid=job_201305240156_0012
Kill Command = /home/satish/work/hadoop-1.0.4/libexec/../bin/hadoop job  -kill job_201305240156_0012
Hadoop job information for Stage-1: number of mappers: 1; number of reducers: 0
2013-05-24 03:51:04,939 Stage-1 map = 0%,  reduce = 0%
2013-05-24 03:51:10,970 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 0.46 sec
2013-05-24 03:51:11,983 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 0.46 sec
2013-05-24 03:51:12,988 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 0.46 sec
2013-05-24 03:51:13,995 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 0.46 sec
2013-05-24 03:51:15,004 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 0.46 sec
2013-05-24 03:51:16,013 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 0.46 sec
2013-05-24 03:51:17,020 Stage-1 map = 100%,  reduce = 100%, Cumulative CPU 0.46 sec
MapReduce Total cumulative CPU time: 460 msec
Ended Job = job_201305240156_0012
MapReduce Jobs Launched: 
Job 0: Map: 1   Cumulative CPU: 0.46 sec   HDFS Read: 848 HDFS Write: 0 SUCCESS
Total MapReduce CPU Time Spent: 460 msec
OK
full_name
Time taken: 19.558 seconds

But this query returns data successfully:

hive (test)> select full_name from states where abbreviation like '%A%';

Result of Query2:
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_201305240156_0011, Tracking URL = http://ubuntu:50030/jobdetails.jsp?jobid=job_201305240156_0011
Kill Command = /home/satish/work/hadoop-1.0.4/libexec/../bin/hadoop job  -kill job_201305240156_0011
Hadoop job information for Stage-1: number of mappers: 1; number of reducers: 0
2013-05-24 03:50:32,163 Stage-1 map = 0%,  reduce = 0%
2013-05-24 03:50:38,193 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 0.47 sec
2013-05-24 03:50:39,196 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 0.47 sec
2013-05-24 03:50:40,199 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 0.47 sec
2013-05-24 03:50:41,206 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 0.47 sec
2013-05-24 03:50:42,210 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 0.47 sec
2013-05-24 03:50:43,221 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 0.47 sec
2013-05-24 03:50:44,227 Stage-1 map = 100%,  reduce = 100%, Cumulative CPU 0.47 sec
MapReduce Total cumulative CPU time: 470 msec
Ended Job = job_201305240156_0011
MapReduce Jobs Launched: 
Job 0: Map: 1   Cumulative CPU: 0.47 sec   HDFS Read: 848 HDFS Write: 115 SUCCESS
Total MapReduce CPU Time Spent: 470 msec
OK
full_name
Alabama
Alaska
Arizona
Arkansas
California
Georgia
Iowa
Louisiana
Massachusetts  
Pennsylvania
Virginia
Washington
Time taken: 20.551 seconds

Thanks
Sai