From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Tue, 12 Apr 2022 15:36:45 +0000 (-0400)
Subject: Doc: update description of random() function.
X-Git-Tag: REL_15_BETA1~183
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d4f109e4a2c028bcd889cc44d84b10fff7d9186b;p=thirdparty%2Fpostgresql.git

Doc: update description of random() function.

Commit 3804539e4 neglected to update the documentation's claim that
random() uses a "linear congruential algorithm".  In hopes of avoiding
the same mistake if someone replaces our PRNG again, just say it's a
deterministic pseudo-random number generator and leave it at that.
Anybody who really wants to know can look in the source code.

COMPATIBILITY NOTE FOR RELEASE NOTES: 3804539e4's commit message
really should have mentioned that the random() sequence after
setseed(), while still repeatable, will differ from what you got
in pre-v15 releases.

Noted by Dagfinn Ilmari Mannsåker; wording suggestion by Dean Rasheed.

Discussion: https://postgr.es/m/875ynfpiru.fsf@wibble.ilmari.org
---

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 0a5c402640d..93ba39eff10 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -1832,8 +1832,9 @@ repeat('Pg', 4) <returnvalue>PgPgPgPg</returnvalue>
    </table>
 
   <para>
-   The <function>random()</function> function uses a simple linear
-   congruential algorithm.  It is fast but not suitable for cryptographic
+   The <function>random()</function> function uses a deterministic
+   pseudo-random number generator.
+   It is fast but not suitable for cryptographic
    applications; see the <xref linkend="pgcrypto"/> module for a more
    secure alternative.
    If <function>setseed()</function> is called, the series of results of