On Tue, Dec 5, 2017 at 6:17 AM, Emilio Lahr-Vivaz <[email protected]> wrote:
> Hello, > > I have two questions related to SearchArguments and predicate push down > that I couldn't find documented anywhere. > > 1. What is the 'columnNames' parameter used for in the searchArgument [1] > method? In my testing, it doesn't seem to make a difference if I pass in > the column I'm filtering, some other column, or even an empty array. > You're right. It isn't used any more, and should be documented as such. It used to be important when the column names weren't passed down to ORC from Hive. I've created ORC-274. > 2. Is it possible to create a predicate on a nested column? From tracing > through the code it doesn't appear to be possible, but wanted to confirm. > For example, I'd like to filter on location.x given a type description > like: struct<id:string,location:struct<x:double,y:double>> > It currently isn't, but it be nice if someone wants to work on it. I've created ORC-275 for that. .. Owen > > Thanks, > > Emilio > > [1]: https://orc.apache.org/api/orc-core/org/apache/orc/Reader. > Options.html#searchArgument-org.apache.hadoop.hive.ql.io. > sarg.SearchArgument-java.lang.String:A- >
