-<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.88 2006/09/18 12:11:36 teodor Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.89 2006/09/25 22:12:24 tgl Exp $ -->
<chapter Id="runtime-config">
<title>Server Configuration</title>
<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
<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>
#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 -
* Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/optimizer/cost.h,v 1.80 2006/09/19 22:49:53 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/optimizer/cost.h,v 1.81 2006/09/25 22:12:24 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#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 */
/*