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Tom Lane bf01e34b55 Tweak genericcostestimate's fudge factor for index size. 
To provide some bias against using a large index when a small one would do
as well, genericcostestimate adds a "fudge factor", which for a long time
was random_page_cost * index_pages/10000.  However, this can grow to be the
dominant term in indexscan cost estimates when the index involved is large
enough, a behavior that was never intended.  Change to a ln(1 + n/10000)
formulation, which has nearly the same behavior up to a few hundred pages
but tails off significantly thereafter.  (A log curve seems correct on
first principles, since what we're trying to account for here is index
descent costs, which are typically logarithmic.)  Per bug #7619 from Niko
Kiirala.

Possibly this change should get back-patched, but I'm hesitant to mess with
cost estimates in stable branches.
 		2012-10-24 16:25:40 -04:00
config Rename USE_INLINE to PG_USE_INLINE 2012-10-09 11:17:33 -03:00
contrib Add context info to OAT_POST_CREATE security hook 2012-10-23 18:24:24 -03:00
doc Add context info to OAT_POST_CREATE security hook 2012-10-23 18:24:24 -03:00
src Tweak genericcostestimate's fudge factor for index size. 2012-10-24 16:25:40 -04:00
.gitignore Add gitignore for mingw/cygwin build outputs 2011-06-09 18:11:47 +02:00
COPYRIGHT Update copyright notices for year 2012. 2012-01-01 18:01:58 -05:00
GNUmakefile.in Make init-po and update-po recursive make targets 2012-06-29 14:01:54 +03:00
Makefile Allow make check in PL directories 2011-02-15 06:52:12 +02:00
README Remove useless whitespace at end of lines 2010-11-23 22:34:55 +02:00
README.git Trivial typo fix. 2010-09-21 14:16:00 -04:00
aclocal.m4 Remove cvs keywords from all files. 2010-09-20 22:08:53 +02:00
configure restore permission bits 2012-10-09 12:08:13 -03:00
configure.in Autoconfiscate selection of 64-bit int type for 64-bit large object API. 2012-10-07 21:52:43 -04:00

README 

PostgreSQL Database Management System
=====================================

This directory contains the source code distribution of the PostgreSQL
database management system.

PostgreSQL is an advanced object-relational database management system
that supports an extended subset of the SQL standard, including
transactions, foreign keys, subqueries, triggers, user-defined types
and functions.  This distribution also contains C language bindings.

PostgreSQL has many language interfaces, many of which are listed here:

	http://www.postgresql.org/download

See the file INSTALL for instructions on how to build and install
PostgreSQL.  That file also lists supported operating systems and
hardware platforms and contains information regarding any other
software packages that are required to build or run the PostgreSQL
system.  Changes between all PostgreSQL releases are recorded in the
file HISTORY.  Copyright and license information can be found in the
file COPYRIGHT.  A comprehensive documentation set is included in this
distribution; it can be read as described in the installation
instructions.

The latest version of this software may be obtained at
http://www.postgresql.org/download/.  For more information look at our
web site located at http://www.postgresql.org/.