On Mon, Apr 29, 2013 at 4:26 PM, Sean McNamara <sean.mcnam...@webtrends.com>wrote:
> If I create a table that has a map<string, string> field, will ORC files > columnarize by the keys in the map? Or will all the pairs in the map be > grouped together? > It will break the map keys into one sub-column and the map values into a separate sub-column. The map keys will end up in a dictionary and the values will be in a different dictionary. It would be interesting to have a map encoding that columnarized low cardinality maps, but I haven't heard anyone thinking about it. -- Owen > My goal is to columnarize the storage of a variable number of fields > (where the names and number of fields are unknown at schema creation). It > does not appear to be possible with RCFILE, and I'm curious if ORC just > adds better type support, or if they also columnarize the fields within > complex types. > > Thanks, > > Sean >
