Okay sounds good. Thank you Julian! On Mon, Aug 14, 2023 at 1:55 PM Julian Hyde <[email protected]> wrote:
> I checked a few other RelMdXxx classes, and. they have private > constructors too. Which makes sense, because you don’t extend metadata > providers by subclassing. You just define your own provider and add it to > the chain. > > RelMdColumnUniqueness has > > public static final RelMetadataProvider SOURCE = > ReflectiveRelMetadataProvider.reflectiveSource( > new RelMdColumnUniqueness(), > BuiltInMetadata.ColumnUniqueness.Handler.class); > > You could define a similar SOURCE in your class that chains > RelMdColumnUniqueness handlers with your own. > > Julian > > > > On Aug 14, 2023, at 9:32 AM, Nick Riasanovsky <[email protected]> wrote: > > > > Hi everyone, > > > > I'm trying to understand why RelMdColumnUniqueness. I have interest in > > subclassing RelMdColumnUniqueness in my project and am unable to do so > > because the constructor is private. Other metadata queries don't appear > to > > have private constructors, such as RelMdRowCount. If anyone has any > > insights or context that would be very helpful. > > > > Thanks, > > Nick Riasanovsky > >
