Log Message:
-----------
Incorporate a couple of recent tuplesort.c improvements into tuplestore.c.
In particular, ensure that enlargement of the memtuples[] array doesn't
fall foul of MaxAllocSize when work_mem is very large, and don't bother
enlarging it if that would force an immediate switch into 'tape' mode anyway.
Modified Files:
--------------
pgsql/src/backend/utils/sort:
tuplestore.c (r1.25 -> r1.26)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/sort/tuplestore.c.diff?r1=1.25&r2=1.26)