Maximum scale and precision for numeric data

[Mehant Baid]

Hey,

Currently the max scale and precision for numeric data types is 19 
(defined here 
<https://github.com/julianhyde/optiq/blob/master/core/src/main/java/org/eigenbase/sql/type/SqlTypeName.java#L90>). 
In Drill maximum precision and scale is 38, so I was hitting a case 
where Optiq is trying to insert casts to cap the precision to be 19. Are 
other projects outside Optiq depending on this limit, if so can we make 
it configurable? If not, I was able to modify the max to be 38 and 
although I hit a few failing test but most of them were straight forward 
to fix.

Thanks
Mehant