From 3804539e48e794781c6145c7f988f5d507418fa8 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sun, 28 Nov 2021 21:32:36 -0500 Subject: Replace random(), pg_erand48(), etc with a better PRNG API and algorithm. Standardize on xoroshiro128** as our basic PRNG algorithm, eliminating a bunch of platform dependencies as well as fundamentally-obsolete PRNG code. In addition, this API replacement will ease replacing the algorithm again in future, should that become necessary. xoroshiro128** is a few percent slower than the drand48 family, but it can produce full-width 64-bit random values not only 48-bit, and it should be much more trustworthy. It's likely to be noticeably faster than the platform's random(), depending on which platform you are thinking about; and we can have non-global state vectors easily, unlike with random(). It is not cryptographically strong, but neither are the functions it replaces. Fabien Coelho, reviewed by Dean Rasheed, Aleksander Alekseev, and myself Discussion: https://postgr.es/m/alpine.DEB.2.22.394.2105241211230.165418@pseudo --- contrib/postgres_fdw/postgres_fdw.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'contrib/postgres_fdw/postgres_fdw.c') diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c index 45a09337d08..f767fdcc6a1 100644 --- a/contrib/postgres_fdw/postgres_fdw.c +++ b/contrib/postgres_fdw/postgres_fdw.c @@ -5158,7 +5158,7 @@ analyze_row_processor(PGresult *res, int row, PgFdwAnalyzeState *astate) if (astate->rowstoskip <= 0) { /* Choose a random reservoir element to replace. */ - pos = (int) (targrows * sampler_random_fract(astate->rstate.randstate)); + pos = (int) (targrows * sampler_random_fract(&astate->rstate.randstate)); Assert(pos >= 0 && pos < targrows); heap_freetuple(astate->rows[pos]); } -- cgit v1.2.3