-
+
Server Configuration
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
PostgreSQL's shared buffers and the
portion of the kernel's disk cache that will be used for
PostgreSQL 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
PostgreSQL, 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).
#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 */
/*