[Postgres-xc-developers] Error Loading json_enhancements

[David E. W. <da...@ju...>]

PGXC Hackers,

I built and installed Andrew Dunstan’s json_enhancements extension. It’s a backport of the 9.3 JSON functions to 9.2. The build worked fine, but when I tried to create the extension I got an error:

    dwheeler=# create extension hstore;
    CREATE EXTENSION
    dwheeler=# create extension json_enhancements;
    ERROR:  unsafe use of pseudo-type "internal"
    DETAIL:  Transition type can not be "internal".

I poked and prodded the file until I figured out the statement it didn’t like. It’s this one:

    CREATE AGGREGATE json_agg(anyelement) (
        SFUNC = json_agg_transfn,
        FINALFUNC = json_agg_finalfn,
        STYPE = internal
    );

Looking at the code, I see that this is forbidden in XC:

  https://github.com/postgres-xc/postgres-xc/blob/master/src/backend/catalog/pg_aggregate.c#L95

Is there a workaround for this?

Thanks,

David