Add first release note detail item.

diff --git a/doc/src/sgml/release.sgml b/doc/src/sgml/release.sgml
index 91439c17f1e670281d39e475a0e8dace14f4ccec..afd5f8ffb3f54ece337277b4fc7c2253f372176e 100644 (file)
--- a/doc/src/sgml/release.sgml
+++ b/doc/src/sgml/release.sgml
@@ -1,5 +1,5 @@
 
 
 
@@ -15,6 +15,15 @@ $Header: /cvsroot/pgsql/doc/src/sgml/release.sgml,v 1.218 2003/10/27 02:51:39 mo
  Performance
 
  IN/NOT IN subqueries are now much more efficient
+  
+  
+   In previous releases, IN/NOT IN subqueries were joined to the
+   upper query by sequentially scanning the subquery looking for
+   a join.  The 7.4 code uses the same sophisticated techniques
+   used by ordinary joins and so is much faster, and is now faster
+   than EXISTS subqueries.
+  
+  
 
 
  Improved GROUP BY processing by using hash buckets