diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index bc5a887044..d9e5985a16 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -3194,8 +3194,8 @@ include 'filename'
         memory allocated by <productname>PostgreSQL</productname>, nor
         does it reserve kernel disk cache; it is used only for estimation
         purposes.  The system also does not assume data remains in
-        the disk cache between queries.  The default is 128 megabytes
-        (<literal>128MB</>).
+        the disk cache between queries.  The default is 4 gigabytes
+        (<literal>4GB</>).
        </para>
       </listitem>
      </varlistentry>
diff --git a/doc/src/sgml/release-9.4.sgml b/doc/src/sgml/release-9.4.sgml
index 4e4f017e43..21c6fc77f7 100644
--- a/doc/src/sgml/release-9.4.sgml
+++ b/doc/src/sgml/release-9.4.sgml
@@ -722,22 +722,22 @@
 
       <listitem>
        <para>
-        Auto-tune <link
-        linkend="guc-effective-cache-size"><varname>effective_cache_size</></link>
-        to be four-times shared buffers (Bruce Momjian, Tom Lane)
+        Increase <link
+        linkend="guc-work-mem"><varname>work_mem</></link> and <link
+        linkend="guc-maintenance-work-mem"><varname>maintenance_work_mem</></link>
+        defaults by four times (Bruce Momjian)
+       </para>
+
+       <para>
+        The new defaults are 4MB and 64MB respectively.
        </para>
       </listitem>
 
       <listitem>
        <para>
-        Increase <link
-        linkend="guc-work-mem"><varname>work_mem</></link> and <link
-        linkend="guc-maintenance-work-mem"><varname>maintenance_work_mem</></link>
-        defaults by four-times (Bruce Momjian)
-       </para>
-
-       <para>
-        The new defaults are 4MB and 64MB respectively.
+        Increase the default setting of <link
+        linkend="guc-effective-cache-size"><varname>effective_cache_size</></link>
+        to 4GB (Bruce Momjian, Tom Lane)
        </para>
       </listitem>
 
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 61685f7c13..6dc0698efe 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -283,7 +283,7 @@
 #cpu_tuple_cost = 0.01			# same scale as above
 #cpu_index_tuple_cost = 0.005		# same scale as above
 #cpu_operator_cost = 0.0025		# same scale as above
-#effective_cache_size = 128MB
+#effective_cache_size = 4GB
 
 # - Genetic Query Optimizer -
 
diff --git a/src/include/optimizer/cost.h b/src/include/optimizer/cost.h
index 3c3c63ae10..75e2afb1e2 100644
--- a/src/include/optimizer/cost.h
+++ b/src/include/optimizer/cost.h
@@ -27,7 +27,7 @@
 #define DEFAULT_CPU_INDEX_TUPLE_COST 0.005
 #define DEFAULT_CPU_OPERATOR_COST  0.0025
 
-#define DEFAULT_EFFECTIVE_CACHE_SIZE  16384		/* measured in pages */
+#define DEFAULT_EFFECTIVE_CACHE_SIZE  524288	/* measured in pages */
 
 typedef enum
 {