Re: FDW for PostgreSQL

At execute_query(), it stores the retrieved rows onto tuplestore of
festate->tuples at once. Doesn't it make problems when remote-
table has very big number of rows?

IIRC, the previous code used cursor feature to fetch a set of rows
to avoid over-consumption of local memory. Do we have some
restriction if we fetch a certain number of rows with FETCH?
It seems to me, we can fetch 1000 rows for example, and tentatively
store them onto the tuplestore within one PG_TRY() block (so, no
need to worry about PQclear() timing), then we can fetch remote
rows again when IterateForeignScan reached end of tuplestore.