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The following page has been changed by EdwardCapriolo: http://wiki.apache.org/hadoop/Hive ------------------------------------------------------------------------------ = What Hive is NOT = 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 you 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. + 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. Hive does not mandate read or written data be in "hive format" - there is no such thing; Hive works equally well on Thrift, RecordIO, control delimited, or your data format.
