postgresql/src/backend/replication/libpqwalreceiver
Tom Lane 4643a2b265 Support retrieval of results in chunks with libpq.
This patch generalizes libpq's existing single-row mode to allow
individual partial-result PGresults to contain up to N rows, rather
than always one row.  This reduces malloc overhead compared to plain
single-row mode, and it is very useful for psql's FETCH_COUNT feature,
since otherwise we'd have to add code (and cycles) to either merge
single-row PGresults into a bigger one or teach psql's
results-printing logic to accept arrays of PGresults.

To avoid API breakage, PQsetSingleRowMode() remains the same, and we
add a new function PQsetChunkedRowsMode() to invoke the more general
case.  Also, PGresults obtained the old way continue to carry the
PGRES_SINGLE_TUPLE status code, while if PQsetChunkedRowsMode() is
used then their status code is PGRES_TUPLES_CHUNK.  The underlying
logic is the same either way, though.

Daniel Vérité, reviewed by Laurenz Albe and myself (and whacked
around a bit by me, so any remaining bugs are my fault)

Discussion: https://postgr.es/m/CAKZiRmxsVTkO928CM+-ADvsMyePmU3L9DQCa9NwqjvLPcEe5QA@mail.gmail.com
2024-04-06 20:45:11 -04:00
..
Makefile Remove distprep 2023-11-06 15:18:04 +01:00
libpqwalreceiver.c Support retrieval of results in chunks with libpq. 2024-04-06 20:45:11 -04:00
meson.build Update copyright for 2024 2024-01-03 20:49:05 -05:00