Along the lines of the equality operator; I have ran into issues trying to pivot a table/result set with a json type due what seemed to be no equality operator.
On Fri, Nov 1, 2013 at 1:50 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote: > Gregory Haase <haaseg@onefreevoice.com> writes: >> The json_data column is not accounted for in pg_stats: > > Ah! I hadn't twigged to the fact that your bloat measurement approach > assumed you had pg_stats entries for all the columns. > >> So I'm not sure if I'd actually qualify this as a "bug", but it appears >> that there is no way to currently get stats on a json data type. > > ANALYZE currently punts on columns that don't have an equality operator, > which json does not. There isn't that much in the way of stats that we > could collect, though I suppose we could still compute average datum width > and null fraction. > > I'm not sure whether there are plans to invent an equality operator for > json.
IMNSO, this may not be a bug, but it's pretty close. All base types should have equality operator as well as other supporting infrastructure that the database itself depends on (in/out and send/receive for example). This is a pretty good example of why.