Avoid O(N^2) behavior when enlarging SPI tuple table in spi_printtup(). For no obvious reason, spi_printtup() was coded to enlarge the tuple pointer table by just 256 slots at a time, rather than doubling the size at each reallocation, as is our usual habit. For very large SPI results, this makes for O(N^2) time spent in repalloc(), which of course soon comes to dominate the runtime. Use the standard doubling approach instead.
This is a longstanding performance bug, so back-patch to all active branches. Neil Conway Branch ------ REL9_3_STABLE Details ------- http://git.postgresql.org/pg/commitdiff/ea989244427f0c98836e1fffdba9fed27a20a79d Modified Files -------------- src/backend/executor/spi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) -- Sent via pgsql-committers mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-committers
