On 11/14/2013 05:06 PM, Merlin Moncure wrote: > On Thu, Nov 14, 2013 at 9:42 AM, Hannu Krosing <ha...@2ndquadrant.com> wrote: >> This is supported by the fact that current functions on json-source >> treat it as json-object (for example key lookup gives you the value >> of latest key and not a list of all matching key values). > yeah. hm. that's a good point. > > Maybe there's a middle ground here: I bet the compatibility issues > would be minimized to an acceptable level if the 'xxx_to_json' > functions maintained their current behaviors; they would construct the > json type in a special internal mode that would behave like the > current type does. Do you have any xxx_to_json usage which can generate a field with multiple equal keys ?
Or is it just about preserving order ? > In other words, the marshalling into binary > structure could happen when: > > *) stored do a column in a table > *) when any modifying routine is called, updating a key, value, etc > *) manually via a function > > but not at cast time. This preserves compatibility for the important > points and allows serialization of structures that are difficult with > the binary mode variant. Seems like this would not play nice with how PostgreSQL type system work in general, but could be a way forward if you say that you really do not need to store the order-preserving, multi-valued json. But in this case it could also be possible for these function to just generate json-format "text", and with proper casts this would act exactly as you describe above, no ? -- Hannu Krosing PostgreSQL Consultant Performance, Scalability and High Availability 2ndQuadrant Nordic OÜ -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers