Thank you!
Very helpful.
Another problem:
I am trying to install Hive 0.4, and I'm coming across the following error
when I try to start bin/hive after building:
java.lang.NoClassDefFoundError: org/apache/hadoop/hive/conf/HiveConf
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:247)
at org.apache.hadoop.util.RunJar.main(RunJar.java:158)
at org.apache.hadoop.mapred.JobShell.run(JobShell.java:54)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:79)
at org.apache.hadoop.mapred.JobShell.main(JobShell.java:68)
Caused by: java.lang.ClassNotFoundException:
org.apache.hadoop.hive.conf.HiveConf
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
... 7 more
Any ideas?
Thanks,
Ryan
On Sat, Oct 10, 2009 at 2:47 PM, Zheng Shao <[email protected]> wrote:
> Yes, we can do this:
>
> SELECT ip, SUM(IF(action = 'action1', 1, 0)), SUM(IF(action = 'action2', 1,
> 0)), SUM(IF(action = 'action3', 1, 0))
> FROM mytable
> GROUP BY ip;
>
> For more details on IF, please refer to:
> http://dev.mysql.com/doc/refman/5.0/en/control-flow-functions.html#function_if
>
> Zheng
>
>
> On Sat, Oct 10, 2009 at 11:42 AM, Ryan LeCompte <[email protected]>wrote:
>
>> Hello all,
>>
>> Very newto Hive (haven't even installed it yet!), but I had a use case
>> that I didn't see demonstrated in any of the tutorial/documentation that
>> I've read thus far.
>>
>> Let's say that I have apache logs that I want to process with Hadoop/Hive.
>> Of course there may be different types of log records all tying back to the
>> same user or IP address or other log attribute. Is there a way to submit a
>> SINGLE Hive query to get back results that may look like:
>>
>>
>> IP Action1Count Action2Count Action3Count
>>
>> .. where the different actions correspond to different log events for that
>> IP address.
>>
>> Do I have to submit 3 different Hive queries here or can I submit a single
>> Hive query? In a regular Java-based map/reduce job, I would have written a
>> custom Writable that would record counts for each of the different actions,
>> and submit it to the reducer using output.collect(IP, customWritable). Here
>> I wouldn't have to submit multiple map/reduce jobs, just 1.
>>
>> Thanks
>> Ryan
>>
>>
>
>
> --
> Yours,
> Zheng
>
