ORC doesn't support that at this time. You can use the ORC file dump utility to find the schema (hive --service orcfiledump _filename_) and then use that when you create the table. ... View more

We did not add transactions to Hive to take workloads out of HBase. HBase is great if you want to do lots of point lookups and range scans. Hive is much better for full table scan workloads. Traditional data warehousing queries fall in the full table scan category (like, find me the year over year average sale by store). These types of operations still require transactions, like when you want to stream data in from your transactional stores, or when you need to update dimension tables. We added transactions to Hive to enable these use cases, so that Hive could be better at what it does as a data warehouse. If your use case more closely approximates a traditional transactional work load (e.g. a shopping cart), definitely don't use Hive. ... View more

Pig does not have any notion of appending results to an existing directory. You could write your Pig job to put results into a temporary directory and then use a DFS command (in or out of Pig) to copy the files into the existing directory that you wanted to append to. Note that this has some dangers (starting jobs may or may not see the copied files, or may only see some of them). Also note that this is exactly what Hive does in its INSERT INTO if you aren't using a lock manager. ... View more