Sophie: postgresql8.4-docs-8.4.12-0.1mdv2010.2 i586

postgresql8.4-docs-8.4.12-0.1mdv2010.2.i586.rpm

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>PostgreSQL 8.4.12 Documentation</TH
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><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="DATATYPE-GEOMETRIC"
>8.8. Geometric Types</A
></H1
><P
>    Geometric data types represent two-dimensional spatial
    objects. <A
HREF="datatype-geometric.html#DATATYPE-GEO-TABLE"
>Table 8-19</A
> shows the geometric
    types available in <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>.  The
    most fundamental type, the point, forms the basis for all of the
    other types.
   </P
><DIV
CLASS="TABLE"
><A
NAME="DATATYPE-GEO-TABLE"
></A
><P
><B
>Table 8-19. Geometric Types</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><COL><COL><COL><COL><THEAD
><TR
><TH
>Name</TH
><TH
>Storage Size</TH
><TH
>Representation</TH
><TH
>Description</TH
></TR
></THEAD
><TBODY
><TR
><TD
><TT
CLASS="TYPE"
>point</TT
></TD
><TD
>16 bytes</TD
><TD
>Point on a plane</TD
><TD
>(x,y)</TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>line</TT
></TD
><TD
>32 bytes</TD
><TD
>Infinite line (not fully implemented)</TD
><TD
>((x1,y1),(x2,y2))</TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>lseg</TT
></TD
><TD
>32 bytes</TD
><TD
>Finite line segment</TD
><TD
>((x1,y1),(x2,y2))</TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>box</TT
></TD
><TD
>32 bytes</TD
><TD
>Rectangular box</TD
><TD
>((x1,y1),(x2,y2))</TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>path</TT
></TD
><TD
>16+16n bytes</TD
><TD
>Closed path (similar to polygon)</TD
><TD
>((x1,y1),...)</TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>path</TT
></TD
><TD
>16+16n bytes</TD
><TD
>Open path</TD
><TD
>[(x1,y1),...]</TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>polygon</TT
></TD
><TD
>40+16n bytes</TD
><TD
>Polygon (similar to closed path)</TD
><TD
>((x1,y1),...)</TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>circle</TT
></TD
><TD
>24 bytes</TD
><TD
>Circle</TD
><TD
>&lt;(x,y),r&gt; (center point and radius)</TD
></TR
></TBODY
></TABLE
></DIV
><P
>    A rich set of functions and operators is available to perform various geometric
    operations such as scaling, translation, rotation, and determining
    intersections.  They are explained in <A
HREF="functions-geometry.html"
>Section 9.11</A
>.
   </P
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN6087"
>8.8.1. Points</A
></H2
><A
NAME="AEN6089"
></A
><P
>     Points are the fundamental two-dimensional building block for geometric
     types.  Values of type <TT
CLASS="TYPE"
>point</TT
> are specified using either of
     the following syntaxes:

</P><PRE
CLASS="SYNOPSIS"
>( <TT
CLASS="REPLACEABLE"
><I
>x</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y</I
></TT
> )
  <TT
CLASS="REPLACEABLE"
><I
>x</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y</I
></TT
></PRE
><P>

     where <TT
CLASS="REPLACEABLE"
><I
>x</I
></TT
> and <TT
CLASS="REPLACEABLE"
><I
>y</I
></TT
> are the respective
     coordinates, as floating-point numbers.
    </P
><P
>     Points are output using the first syntax.
    </P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN6101"
>8.8.2. Line Segments</A
></H2
><A
NAME="AEN6103"
></A
><A
NAME="AEN6105"
></A
><P
>     Line segments (<TT
CLASS="TYPE"
>lseg</TT
>) are represented by pairs of points.
     Values of type <TT
CLASS="TYPE"
>lseg</TT
> are specified using any of the following
     syntaxes:

</P><PRE
CLASS="SYNOPSIS"
>[ ( <TT
CLASS="REPLACEABLE"
><I
>x1</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y1</I
></TT
> ) , ( <TT
CLASS="REPLACEABLE"
><I
>x2</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y2</I
></TT
> ) ]
( ( <TT
CLASS="REPLACEABLE"
><I
>x1</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y1</I
></TT
> ) , ( <TT
CLASS="REPLACEABLE"
><I
>x2</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y2</I
></TT
> ) )
  ( <TT
CLASS="REPLACEABLE"
><I
>x1</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y1</I
></TT
> ) , ( <TT
CLASS="REPLACEABLE"
><I
>x2</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y2</I
></TT
> )
    <TT
CLASS="REPLACEABLE"
><I
>x1</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y1</I
></TT
>   ,   <TT
CLASS="REPLACEABLE"
><I
>x2</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y2</I
></TT
></PRE
><P>

     where
     <TT
CLASS="LITERAL"
>(<TT
CLASS="REPLACEABLE"
><I
>x1</I
></TT
>,<TT
CLASS="REPLACEABLE"
><I
>y1</I
></TT
>)</TT
>
     and
     <TT
CLASS="LITERAL"
>(<TT
CLASS="REPLACEABLE"
><I
>x2</I
></TT
>,<TT
CLASS="REPLACEABLE"
><I
>y2</I
></TT
>)</TT
>
     are the end points of the line segment.
    </P
><P
>     Line segments are output using the first syntax.
    </P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN6134"
>8.8.3. Boxes</A
></H2
><A
NAME="AEN6136"
></A
><A
NAME="AEN6138"
></A
><P
>     Boxes are represented by pairs of points that are opposite
     corners of the box.
     Values of type <TT
CLASS="TYPE"
>box</TT
> are specified using any of the following
     syntaxes:

</P><PRE
CLASS="SYNOPSIS"
>( ( <TT
CLASS="REPLACEABLE"
><I
>x1</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y1</I
></TT
> ) , ( <TT
CLASS="REPLACEABLE"
><I
>x2</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y2</I
></TT
> ) )
  ( <TT
CLASS="REPLACEABLE"
><I
>x1</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y1</I
></TT
> ) , ( <TT
CLASS="REPLACEABLE"
><I
>x2</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y2</I
></TT
> )
    <TT
CLASS="REPLACEABLE"
><I
>x1</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y1</I
></TT
>   ,   <TT
CLASS="REPLACEABLE"
><I
>x2</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y2</I
></TT
></PRE
><P>

     where
     <TT
CLASS="LITERAL"
>(<TT
CLASS="REPLACEABLE"
><I
>x1</I
></TT
>,<TT
CLASS="REPLACEABLE"
><I
>y1</I
></TT
>)</TT
>
     and
     <TT
CLASS="LITERAL"
>(<TT
CLASS="REPLACEABLE"
><I
>x2</I
></TT
>,<TT
CLASS="REPLACEABLE"
><I
>y2</I
></TT
>)</TT
>
     are any two opposite corners of the box.
    </P
><P
>     Boxes are output using the second syntax.
    </P
><P
>     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, in that order.
    </P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN6163"
>8.8.4. Paths</A
></H2
><A
NAME="AEN6165"
></A
><P
>     Paths are represented by lists of connected points. Paths can be
     <I
CLASS="FIRSTTERM"
>open</I
>, where
     the first and last points in the list are considered not connected, or
     <I
CLASS="FIRSTTERM"
>closed</I
>,
     where the first and last points are considered connected.
    </P
><P
>     Values of type <TT
CLASS="TYPE"
>path</TT
> are specified using any of the following
     syntaxes:

</P><PRE
CLASS="SYNOPSIS"
>[ ( <TT
CLASS="REPLACEABLE"
><I
>x1</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y1</I
></TT
> ) , ... , ( <TT
CLASS="REPLACEABLE"
><I
>xn</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>yn</I
></TT
> ) ]
( ( <TT
CLASS="REPLACEABLE"
><I
>x1</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y1</I
></TT
> ) , ... , ( <TT
CLASS="REPLACEABLE"
><I
>xn</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>yn</I
></TT
> ) )
  ( <TT
CLASS="REPLACEABLE"
><I
>x1</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y1</I
></TT
> ) , ... , ( <TT
CLASS="REPLACEABLE"
><I
>xn</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>yn</I
></TT
> )
  ( <TT
CLASS="REPLACEABLE"
><I
>x1</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y1</I
></TT
>   , ... ,   <TT
CLASS="REPLACEABLE"
><I
>xn</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>yn</I
></TT
> )
    <TT
CLASS="REPLACEABLE"
><I
>x1</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y1</I
></TT
>   , ... ,   <TT
CLASS="REPLACEABLE"
><I
>xn</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>yn</I
></TT
></PRE
><P>

     where the points are the end points of the line segments
     comprising the path.  Square brackets (<TT
CLASS="LITERAL"
>[]</TT
>) indicate
     an open path, while parentheses (<TT
CLASS="LITERAL"
>()</TT
>) indicate a
     closed path.  When the outermost parentheses are omitted, as
     in the third through fifth syntaxes, a closed path is assumed.
    </P
><P
>     Paths are output using the first or second syntax, as appropriate.
    </P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN6196"
>8.8.5. Polygons</A
></H2
><A
NAME="AEN6198"
></A
><P
>     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.
    </P
><P
>     Values of type <TT
CLASS="TYPE"
>polygon</TT
> are specified using any of the
     following syntaxes:

</P><PRE
CLASS="SYNOPSIS"
>( ( <TT
CLASS="REPLACEABLE"
><I
>x1</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y1</I
></TT
> ) , ... , ( <TT
CLASS="REPLACEABLE"
><I
>xn</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>yn</I
></TT
> ) )
  ( <TT
CLASS="REPLACEABLE"
><I
>x1</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y1</I
></TT
> ) , ... , ( <TT
CLASS="REPLACEABLE"
><I
>xn</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>yn</I
></TT
> )
  ( <TT
CLASS="REPLACEABLE"
><I
>x1</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y1</I
></TT
>   , ... ,   <TT
CLASS="REPLACEABLE"
><I
>xn</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>yn</I
></TT
> )
    <TT
CLASS="REPLACEABLE"
><I
>x1</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y1</I
></TT
>   , ... ,   <TT
CLASS="REPLACEABLE"
><I
>xn</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>yn</I
></TT
></PRE
><P>

     where the points are the end points of the line segments
     comprising the boundary of the polygon.
    </P
><P
>     Polygons are output using the first syntax.
    </P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN6221"
>8.8.6. Circles</A
></H2
><A
NAME="AEN6223"
></A
><P
>     Circles are represented by a center point and radius.
     Values of type <TT
CLASS="TYPE"
>circle</TT
> are specified using any of the
     following syntaxes:

</P><PRE
CLASS="SYNOPSIS"
>&lt; ( <TT
CLASS="REPLACEABLE"
><I
>x</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y</I
></TT
> ) , <TT
CLASS="REPLACEABLE"
><I
>r</I
></TT
> &gt;
( ( <TT
CLASS="REPLACEABLE"
><I
>x</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y</I
></TT
> ) , <TT
CLASS="REPLACEABLE"
><I
>r</I
></TT
> )
  ( <TT
CLASS="REPLACEABLE"
><I
>x</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y</I
></TT
> ) , <TT
CLASS="REPLACEABLE"
><I
>r</I
></TT
>
    <TT
CLASS="REPLACEABLE"
><I
>x</I
></TT
> , <TT
CLASS="REPLACEABLE"
><I
>y</I
></TT
>   , <TT
CLASS="REPLACEABLE"
><I
>r</I
></TT
></PRE
><P>

     where
     <TT
CLASS="LITERAL"
>(<TT
CLASS="REPLACEABLE"
><I
>x</I
></TT
>,<TT
CLASS="REPLACEABLE"
><I
>y</I
></TT
>)</TT
>
     is the center point and <TT
CLASS="REPLACEABLE"
><I
>r</I
></TT
> is the radius of the
     circle.
    </P
><P
>     Circles are output using the first syntax.
    </P
></DIV
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