docs: PG 12 relnotes, update self-join item to mention ctid

Reported-by: Robert Haas
Discussion: https://postgr.es/m/CA+TgmoY==TZwk-4cM3Usebq1f=j7Hpm1brFbk1v48h45wsWzzg@mail.gmail.com

diff --git a/doc/src/sgml/release-12.sgml b/doc/src/sgml/release-12.sgml
index 27844df389236e72534b9fa5043b39150bc5d9e4..76abc95b128f2f404e0909f8e9fd052d960e927a 100644 (file)
--- a/doc/src/sgml/release-12.sgml
+++ b/doc/src/sgml/release-12.sgml
@@ -835,7 +835,7 @@ Author: Tom Lane <tgl@sss.pgh.pa.us>
 -->
 
        <para>
-        Improve optimization of self-joins (Tom Lane)
+        Improve optimization of self-joins involving columns of type tid (Tom Lane)
        </para>
       </listitem>