doc: Add advice on updating checkpoint_segments to max_wal_size

with suggestion from Michael Paquier

diff --git a/doc/src/sgml/release-9.5.sgml b/doc/src/sgml/release-9.5.sgml
index d5b68e73ef5bb2623107cbf69e2d33b3ac82c49a..92443e43c193d9bc0831a4c299b8a7fb37aa088d 100644 (file)
--- a/doc/src/sgml/release-9.5.sgml
+++ b/doc/src/sgml/release-9.5.sgml
@@ -152,6 +152,22 @@
      
     
 
+    
+     
+      The configuration parameter checkpoint_segments has
+      been removed.  Its place is taken by the new
+      setting .  If you had previously
+      tuned checkpoint_segments, the following formula will
+      give you an approximately equivalent setting:
+
+max_wal_size = (3 * checkpoint_segments) * 16MB
+
+      Note that the default setting for max_wal_size is
+      much higher than the default checkpoint_segments used
+      to be, so setting this might no longer be necessary.
+     
+    
+