pgsql: Doc: document libpq's restriction to INT_MAX rows in a PGresult.

Doc: document libpq's restriction to INT_MAX rows in a PGresult.

As long as PQntuples, PQgetvalue, etc, use "int" for row numbers, we're
pretty much stuck with this limitation. The documentation formerly stated
that the result of PQntuples "might overflow on 32-bit operating systems",
which is just nonsense: that's not where the overflow would happen, and
if you did reach an overflow it would not be on a 32-bit machine, because
you'd have OOM'd long since.

Discussion: https://postgr.es/m/CA+FnnTxyLWyjY1goewmJNxC==HQCCF4fKkoCTa9qR36oRAHDPw@mail.gmail.com

Branch
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REL9_4_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/2338ad26374ef27c7601bb5a1517a6a0c82ef94e

Modified Files
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doc/src/sgml/libpq.sgml | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)