Fix assorted misstatements and poor wording in the descriptions of the I/O

formats for geometric types.  Per bug #5536 from Jon Strait, and my own
testing.

Back-patch to all supported branches, since this doco has been wrong right
along -- we certainly haven't changed the I/O behavior of these types in
many years.
This commit is contained in:
Tom Lane 2010-07-03 04:03:06 +00:00
parent 276a8f4e99
commit 4b200a2769

View File

@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/datatype.sgml,v 1.249 2010/06/29 00:03:39 petere Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/datatype.sgml,v 1.250 2010/07/03 04:03:06 tgl Exp $ -->
<chapter id="datatype">
<title>Data Types</title>
@ -3073,8 +3073,9 @@ SELECT person.name, holidays.num_weeks FROM person, holidays
</indexterm>
<para>
Points are the fundamental two-dimensional building block for geometric types.
Values of type <type>point</type> are specified using the following syntax:
Points are the fundamental two-dimensional building block for geometric
types. Values of type <type>point</type> are specified using either of
the following syntaxes:
<synopsis>
( <replaceable>x</replaceable> , <replaceable>y</replaceable> )
@ -3084,6 +3085,10 @@ SELECT person.name, holidays.num_weeks FROM person, holidays
where <replaceable>x</> and <replaceable>y</> are the respective
coordinates, as floating-point numbers.
</para>
<para>
Points are output using the first syntax.
</para>
</sect2>
<sect2>
@ -3099,9 +3104,11 @@ SELECT person.name, holidays.num_weeks FROM person, holidays
<para>
Line segments (<type>lseg</type>) are represented by pairs of points.
Values of type <type>lseg</type> are specified using the following syntax:
Values of type <type>lseg</type> are specified using any of the following
syntaxes:
<synopsis>
[ ( <replaceable>x1</replaceable> , <replaceable>y1</replaceable> ) , ( <replaceable>x2</replaceable> , <replaceable>y2</replaceable> ) ]
( ( <replaceable>x1</replaceable> , <replaceable>y1</replaceable> ) , ( <replaceable>x2</replaceable> , <replaceable>y2</replaceable> ) )
( <replaceable>x1</replaceable> , <replaceable>y1</replaceable> ) , ( <replaceable>x2</replaceable> , <replaceable>y2</replaceable> )
<replaceable>x1</replaceable> , <replaceable>y1</replaceable> , <replaceable>x2</replaceable> , <replaceable>y2</replaceable>
@ -3113,6 +3120,10 @@ SELECT person.name, holidays.num_weeks FROM person, holidays
<literal>(<replaceable>x2</replaceable>,<replaceable>y2</replaceable>)</literal>
are the end points of the line segment.
</para>
<para>
Line segments are output using the first syntax.
</para>
</sect2>
<sect2>
@ -3129,7 +3140,8 @@ SELECT person.name, holidays.num_weeks FROM person, holidays
<para>
Boxes are represented by pairs of points that are opposite
corners of the box.
Values of type <type>box</type> are specified using the following syntax:
Values of type <type>box</type> are specified using any of the following
syntaxes:
<synopsis>
( ( <replaceable>x1</replaceable> , <replaceable>y1</replaceable> ) , ( <replaceable>x2</replaceable> , <replaceable>y2</replaceable> ) )
@ -3145,10 +3157,13 @@ SELECT person.name, holidays.num_weeks FROM person, holidays
</para>
<para>
Boxes are output using the first syntax.
Boxes are output using the second syntax.
</para>
<para>
Any two opposite corners can be supplied on input, but the values
will be reordered as needed to store the
upper right and lower left corners.
upper right and lower left corners, in that order.
</para>
</sect2>
@ -3168,11 +3183,12 @@ SELECT person.name, holidays.num_weeks FROM person, holidays
</para>
<para>
Values of type <type>path</type> are specified using the following syntax:
Values of type <type>path</type> are specified using any of the following
syntaxes:
<synopsis>
( ( <replaceable>x1</replaceable> , <replaceable>y1</replaceable> ) , ... , ( <replaceable>xn</replaceable> , <replaceable>yn</replaceable> ) )
[ ( <replaceable>x1</replaceable> , <replaceable>y1</replaceable> ) , ... , ( <replaceable>xn</replaceable> , <replaceable>yn</replaceable> ) ]
( ( <replaceable>x1</replaceable> , <replaceable>y1</replaceable> ) , ... , ( <replaceable>xn</replaceable> , <replaceable>yn</replaceable> ) )
( <replaceable>x1</replaceable> , <replaceable>y1</replaceable> ) , ... , ( <replaceable>xn</replaceable> , <replaceable>yn</replaceable> )
( <replaceable>x1</replaceable> , <replaceable>y1</replaceable> , ... , <replaceable>xn</replaceable> , <replaceable>yn</replaceable> )
<replaceable>x1</replaceable> , <replaceable>y1</replaceable> , ... , <replaceable>xn</replaceable> , <replaceable>yn</replaceable>
@ -3181,7 +3197,8 @@ SELECT person.name, holidays.num_weeks FROM person, holidays
where the points are the end points of the line segments
comprising the path. Square brackets (<literal>[]</>) indicate
an open path, while parentheses (<literal>()</>) indicate a
closed path.
closed path. When the outermost parentheses are omitted, as
in the third through fifth syntaxes, a closed path is assumed.
</para>
<para>
@ -3199,12 +3216,12 @@ SELECT person.name, holidays.num_weeks FROM person, holidays
<para>
Polygons are represented by lists of points (the vertexes of the
polygon). Polygons are very similar to closed paths, but are
stored differently
and have their own set of support routines.
stored differently and have their own set of support routines.
</para>
<para>
Values of type <type>polygon</type> are specified using the following syntax:
Values of type <type>polygon</type> are specified using any of the
following syntaxes:
<synopsis>
( ( <replaceable>x1</replaceable> , <replaceable>y1</replaceable> ) , ... , ( <replaceable>xn</replaceable> , <replaceable>yn</replaceable> ) )
@ -3231,7 +3248,8 @@ SELECT person.name, holidays.num_weeks FROM person, holidays
<para>
Circles are represented by a center point and radius.
Values of type <type>circle</type> are specified using the following syntax:
Values of type <type>circle</type> are specified using any of the
following syntaxes:
<synopsis>
&lt; ( <replaceable>x</replaceable> , <replaceable>y</replaceable> ) , <replaceable>r</replaceable> &gt;
@ -3241,8 +3259,9 @@ SELECT person.name, holidays.num_weeks FROM person, holidays
</synopsis>
where
<literal>(<replaceable>x</replaceable>,<replaceable>y</replaceable>)</literal>
is the center point and <replaceable>r</replaceable> is the radius of the circle.
<literal>(<replaceable>x</replaceable>,<replaceable>y</replaceable>)</>
is the center point and <replaceable>r</replaceable> is the radius of the
circle.
</para>
<para>