Here is a nice video from Cloudera on a HIVE tutorial. I wonder what would happen if they put a real analytical system and not just basic analytics and reporting … like R or SPSS or JMP or SAS on big database system like Hadoop (including some text mined data from legacy company documents)
Unlike Oracle or other data base systems, Hadoop is free now and in reasonable future (like MySQL used to be before acquired by big fish Sun acquired by bigger Oracle).
Hive is a data warehouse infrastructure built on top of Hadoop that provides tools to enable easy data summarization, adhoc querying and analysis of large datasets data stored in Hadoop files
Hive is based on Hadoop which is a batch processing system. Accordingly, this system does not and cannot promise low latencies on queries. The paradigm here is strictly of submitting jobs and being notified when the jobs are completed as opposed to real time queries. As a result it should not be compared with systems like Oracle where analysis is done on a significantly smaller amount of data but the analysis proceeds much more iteratively with the response times between iterations being less than a few minutes. For Hive queries response times for even the smallest jobs can be of the order of 5-10 minutes and for larger jobs this may even run into hours.
If your input data is small you can execute a query in a short time. For example, if a table has 100 rows you can ‘set mapred.reduce.tasks=1’ and ‘set mapred.map.tasks=1’ and the query time will be ~15 seconds.