Seems like useful functionality that would be great to have in Impala. There was an earlier attempt to do this that didn't make it in - I'm not sure that the approach was quite right: https://gerrit.cloudera.org/#/c/1201/1 . I'm not sure what the exact problems were but I remember we didn't think it was quite the right approach.
I think we'd need to talk through a design first because there are a lot of considerations and we want to make sure to get it right. I had some initial questions that I'd want to think through before adding a JSON scanner. - What JSON does it accept? - How do we declare a table schema and map it to the JSON - How does it handle missing or extra fields - does it just return null or drop the fields? What if the field type is wrong? - How do the numeric types work? JSON only supports floating point, but I think many people would like to store higher-precision decimal or 64-bit integer types (which is technically outside of the JSON standard). - Will it support codegen? If not, is it written in a way that allows it in future? Cheers, Tim - Tim On Tue, Apr 18, 2017 at 8:52 AM, Jim Apple <jbap...@cloudera.com> wrote: > On Mon, Apr 17, 2017 at 8:02 PM, yu feng <olaptes...@gmail.com> wrote: > > > Hi impala community: > > I am Newly join to Impala, > > > Welcome! > > I want to know what is the attitude of impala > > community for supporting json format. > > > I am in favor of it. I am only one person, though - anybody else object to > JSON support? > > If this match the roadmap, maybe I > > can make some contribution. > > > > I do not recall much talk about Apache Impala's roadmap since we joined the > ASF. Perhaps I missed a thread about it? >
