Increase default value of effective_cache_size to 128MB, per discussion.

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index c80973a3be43783f4e97b013cd636d70f162caca..c6d0271bfe3dfc1230c55be316f965e4181ae867 100644 (file)
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -1905,7 +1905,7 @@ archive_command = 'copy "%p" /mnt/server/archivedir/"%f"'  # Windows
       <listitem>
        <para>
         Sets the planner's assumption about the effective size of the
-        disk cache that is available to a single index scan.  This is
+        disk cache that is available to a single query.  This is
         factored into estimates of the cost of using an index; a
         higher value makes it more likely index scans will be used, a
         lower value makes it more likely sequential scans will be
@@ -1913,13 +1913,13 @@ archive_command = 'copy "%p" /mnt/server/archivedir/"%f"'  # Windows
         <productname>PostgreSQL</productname>'s shared buffers and the
         portion of the kernel's disk cache that will be used for
         <productname>PostgreSQL</productname> data files.  Also, take
-        into account the expected number of concurrent queries using
-        different indexes, since they will have to share the available
+        into account the expected number of concurrent queries on different
+        tables, since they will have to share the available
         space.  This parameter has no effect on the size of shared
         memory allocated by <productname>PostgreSQL</productname>, nor
         does it reserve kernel disk cache; it is used only for
         estimation purposes.  The value is measured in disk pages,
-        which are normally 8192 bytes each. The default is 1000.
+        which are normally 8192 bytes each. The default is 16384 (128 MB).
        </para>
       </listitem>
      </varlistentry>

diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 40a205a501a6b97606ad910d2431862b62c125b2..13408899dc37c5fe11a35e5af56331d1005e73ba 100644 (file)
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -195,7 +195,7 @@
 #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 = 8000kB
+#effective_cache_size = 128MB
 
 # - Genetic Query Optimizer -
 

diff --git a/src/include/optimizer/cost.h b/src/include/optimizer/cost.h
index 6e72b2c6ca802b51a22b9c882770c47f7dc25f3d..6a2972c7b34f632a37483ef996df4524304c3d0b 100644 (file)
--- 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  1000     /* measured in pages */
+#define DEFAULT_EFFECTIVE_CACHE_SIZE  16384    /* measured in pages */
 
 
 /*