can be generated in a buffer and then sent to the frontend in a single
libpq call.  This solves problems with NOTICE and ERROR messages generated
in the middle of a data message or COPY OUT operation.

This fixes a few of the problems Hiroshi Inoue complained of, but
I have not touched the rewrite-related issues.

_copyResult didn't copy subPlan structure completely.  _copyAgg is still
busted, apparently because of changes from EXCEPT/INTERSECT patch
(get_agg_tlist_references is no longer sufficient to find all aggregates).
No time to look at that tonight, however.

so remove them from MergeJoin node.  Hack together a partial
solution for commuted mergejoin operators --- yesterday
a mergejoin int4 = int8 would crash if the planner decided to
commute it, today it works.  The planner's representation of
mergejoins really needs a rewrite though.
Also, further testing of mergejoin ops in opr_sanity regress test.

Define the JoinExpr node.

 file early enough to use in nodes/.
Try to be more complete for rules on generating parse.h,
 but it still does not work any better than before. Should be able to
 make correctly if parser/gram.y is updated even without a "make clean"
 but so far not there yet.

complaints in UNION regress test.  Probably still need some more node
types to be handled here, but I'm done for the day...

Jan

only once per SELECT, not once per tuple.  10% here, 10% there,
pretty soon you're talking about real speedups ...