Wait, If you _do_ set a projection on the scanner that does not include the
keys, then they won't be returned (and won't appear on the projection's
schema).
Note that this does not mean that you can't set predicates on the key, it's
just that they'll be evaluated server side, but the key won't actually be
returned.
Maybe I'm misunderstanding what you're saying?
Care to post a gist with the offending code?
-david
On Fri, Sep 9, 2016 at 8:26 AM, Jordan Birdsell <jordantbirds...@gmail.com>
wrote:
> Hey David,
>
> Yep, i'm sure, taking a look at the scan_configuration class, the issue
> seems to be here:
>
> Status ScanConfiguration::SetProjectedColumnIndexes(const vector<int>&
> col_indexes) {
> ....
> RETURN_NOT_OK*(s->Reset(cols, 0));*
> ....
>
> In the SetProjectedColumnIndexes method (which is also used by
> SetProjectedColumnNames), we're setting the schema without the index.
>
> There are probably a couple of ways to address this:
>
> 1. Check if all key columns are in the projection, and if so, maintain
> the key.
> 2. Provide an optional parameter to be able to set the key to users
> preference for the new projection. This would be beneficial for cases
> where
> the user may want to create a new table based on their projection.
>
> Thoughts?
>
> Jordan
>
> On Fri, Sep 9, 2016 at 11:08 AM David Alves <davidral...@gmail.com> wrote:
>
> > Hi Jordan
> >
> > KuduScanner::GetProjectionSchema returns the schema of the projection
> > that was previously set on the scanner. If you don't a projection it
> should
> > indeed return all the columns.
> > Are you sure you didn't set a projection (with SetProjectedColumnNames
> > or SetProjectedColumnIndexes) that excluded the key?
> >
> > Best
> > David
> >
> > On Fri, Sep 9, 2016 at 5:16 AM, Jordan Birdsell <
> jordantbirds...@gmail.com
> > >
> > wrote:
> >
> > > Hey folks,
> > >
> > > i was doing some work on KUDU-854
> > > <https://issues.apache.org/jira/browse/KUDU-854> and when testing the
> > > KuduScanner::GetProjectionSchema method call, found that the key was
> > being
> > > dropped, which makes this much more challenging to test. Any ideas if
> it
> > is
> > > intended to drop the key information in a scanner projection? I would
> > > imagine this could prevent functionality like creating new tables from
> a
> > > projection.
> > >
> > > Thanks,
> > > Jordan
> > >
> >
>
