On 12/12/2014 08:20 PM, Tom Lane wrote:
We can't just add the operator and worry about usability later; if we're thinking we might want to introduce such an automatic transformation, we have to be sure the new operator is defined in a way that allows the transformation to not change any semantics. What that means in this case is that if (jsonb ->> 'foo')::numeric would have succeeded, (jsonb ->># 'foo') has to succeed; which means it'd better be willing to attempt conversion of string values to numeric, not just throw an error on sight.
Well, I'm not 100% convinced about the magic transformation being a good thing.
Json numbers are distinct from strings, and part of the justification for this is to extract a numeric datum from jsonb exactly as stored, on performance grounds. So turning round now and making that turn a string into a number if possible seems to me to be going in the wrong direction.
cheers andrew -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
