Re: random() function documentation
Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>
From: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-hackers@lists.postgresql.org
Date: 2022-04-11T19:00:26Z
Lists: pgsql-hackers
Tom Lane <tgl@sss.pgh.pa.us> writes: > =?utf-8?Q?Dagfinn_Ilmari_Manns=C3=A5ker?= <ilmari@ilmari.org> writes: >> I just noticed that the since the random() rewrite¹, the documentation's >> claim² that it "uses a simple linear congruential algorithm" is no >> longer accurate (xoroshiro128** is an xorshift variant, which is a >> linear-feedback shift register algorithm). > >> I don't have a suggestion for the exact wording, since I don't know >> whether xoroshiro128** qualifies as "simple", or to what level of >> specificity we want to document the algorithm. > > How about we just say "uses a linear-feedback shift register algorithm"? That works for me. Nice and simple, and not overly specific. Should we perhaps also add a warning that the same seed is not guaranteed to produce the same sequence across different (major?) versions? > "Simple" is in the eye of the beholder anyway. Indeed. > regards, tom lane - ilmari
Commits
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Doc: update description of random() function.
- d4f109e4a2c0 15.0 landed
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Replace random(), pg_erand48(), etc with a better PRNG API and algorithm.
- 3804539e48e7 15.0 cited