Go to file
Tomas Vondra c4c3400885 Use the built-in float datatypes to implement geometric types
This patch makes the geometric operators and functions use the exported
function of the float4/float8 datatypes.  The main reason of doing so is
to check for underflow and overflow, and to handle NaNs consciously.

The float datatypes consider NaNs values to be equal and greater than
all non-NaN values.  This change considers NaNs equal only for equality
operators.  The placement operators, contains, overlaps, left/right of
etc. continue to return false when NaNs are involved.  We don't need
to worry about them being considered greater than any-NaN because there
aren't any basic comparison operators like less/greater than for the
geometric datatypes.

The changes may be summarised as:

* Check for underflow, overflow and division by zero
* Consider NaN values to be equal
* Return NULL when the distance is NaN for all closest point operators
* Favour not-NaN over NaN where it makes sense

The patch also replaces all occurrences of "double" as "float8".  They
are the same, but were used inconsistently in the same file.

Author: Emre Hasegeli
Reviewed-by: Kyotaro Horiguchi, Tomas Vondra

Discussion: https://www.postgresql.org/message-id/CAE2gYzxF7-5djV6-cEvqQu-fNsnt%3DEqbOURx7ZDg%2BVv6ZMTWbg%40mail.gmail.com
2018-08-16 19:56:11 +02:00
config Require a C99-compliant snprintf(), and remove related workarounds. 2018-08-16 13:01:09 -04:00
contrib Spell "partitionwise" consistently. 2018-08-09 10:43:18 +03:00
doc doc: Update broken links 2018-08-14 22:54:52 +02:00
src Use the built-in float datatypes to implement geometric types 2018-08-16 19:56:11 +02:00
.dir-locals.el Update documentation editor setup instructions 2018-07-13 21:23:41 +02:00
.gitattributes Remove contrib/tsearch2. 2017-02-13 11:06:11 -05:00
.gitignore Support for optimizing and emitting code in LLVM JIT provider. 2018-03-22 11:05:22 -07:00
aclocal.m4 Add configure infrastructure (--with-llvm) to enable LLVM support. 2018-03-20 17:26:25 -07:00
configure Require a C99-compliant snprintf(), and remove related workarounds. 2018-08-16 13:01:09 -04:00
configure.in Require a C99-compliant snprintf(), and remove related workarounds. 2018-08-16 13:01:09 -04:00
COPYRIGHT Update copyright for 2018 2018-01-02 23:30:12 -05:00
GNUmakefile.in Remove unwanted "garbage cleanup" logic in Makefiles. 2018-08-08 14:32:29 -04:00
HISTORY Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00
Makefile Fix non-GNU makefiles for AIX make. 2017-11-30 00:57:22 -08:00
README Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00
README.git Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00

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:

	https://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.  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
https://www.postgresql.org/download/.  For more information look at our
web site located at https://www.postgresql.org/.