Doc: update description of random() function.

tglsfdc · tglsfdc · commit d4f109e4a2c0 · 2022-04-12T11:36:45.000-04:00
Commit 3804539 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: 3804539'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
@@ -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
