Impala does not have control of the physical locations of the HDFS blocks underlying Impala tables. The tables in Impala are backed by files on HDFS and those files are chopped into blocks and distributed according to your HDFS configuration, but for all practical purposes the blocks are distributed round-robin among the data nodes (grossly simplified). Impala queries typically run on all data nodes that store data relevant to answering a parcitular query, so given a fixed amount of data, you can indirectly control Impala's degree of (inter-node) parallelism by changing the HDFS block size. More blocks == more parallelism. If you are interested in learning about Impala, you may also find the CIDR paper useful: http://www.cidrdb.org/cidr2015/Papers/CIDR15_Paper28.pdf ... View more

I'm afraid that Impala currently does not support writing Avro data. Even though you can enable experimental support, we strongly advise against that, and instead recomment using another tool such as Hive or Kite to do the conversion. My apologies for the inconvenience. ... View more

Impala currently does not support truncating an individual partition, so that syntax error you get from the shell is expected. I am not sure why the statement appears to work from Hue. The TRUNCATE TABLE ... PARTITION syntax is not supported, so I don't see how this would work. Perhaps the error is somehow not properly shown/propagated to Hue?   ... View more

Thanks for the update. I can reproduce the issue, but only when the target partition is empty. As soon as I add some data, compute incremental stats works as expected. So I'm still thinking you are hitting an edge case with an empty partition?   ... View more