CC: yu feng <[email protected]> Yu, I think I haven't seen you post before here. This mailing list sets reply-to that doesn't include the email address of the poster. Perhaps you already knew this or were already subscribed to that list, but I have CCed you just in case.
On Tue, Apr 18, 2017 at 10:55 AM, Alexander Behm <[email protected]> wrote: > The existing attempt used the Rapidjson library to do the parsing. > Unfortunately, the Rapidjson API is not very convenient for Impala because > it returns typed data, i.e., it internally converts to > float/double/int/whatever which is problematic for decimal (among others). > Ideally, we would use the same Impala code to convert data types from > strings. > > On Tue, Apr 18, 2017 at 9:27 AM, Tim Armstrong <[email protected]> > wrote: > > > 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 <[email protected]> wrote: > > > > > On Mon, Apr 17, 2017 at 8:02 PM, yu feng <[email protected]> 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? > > > > > >
