doc PG 19 relnotes: add UTF-8 case folding performance item

Reported-by: Andreas Karlsson
Discussion: https://postgr.es/m/9dae1593-4441-4a20-a1ab-ce5018db9878@proxel.se

diff --git a/doc/src/sgml/release-19.sgml b/doc/src/sgml/release-19.sgml
index 008405623e1d0b6014dac0c7be0e3b7dac18193d..f265ac00eb2687fae82bb527dd68768a62021c27 100644 (file)
--- a/doc/src/sgml/release-19.sgml
+++ b/doc/src/sgml/release-19.sgml
@@ -753,6 +753,18 @@ Improve performance of internal row deformation (David Rowley)
 </para>
 </listitem>
 
+<!--
+Author: Jeff Davis <jdavis@postgresql.org>
+2026-01-06 [c4ff35f10] ICU: use UTF8-optimized case conversion API
+-->
+
+<listitem>
+<para>
+Improve performance of repeated UTF-8 case-folding operations (Andreas Karlsson)
+<ulink url="&commit_baseurl;c4ff35f10">&sect;</ulink>
+</para>
+</listitem>
+
 <!--
 Author: Michael Paquier <michael@paquier.xyz>
 2026-03-16 [bfa3c4f10] Optimize hash index bulk-deletion with streaming read