<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >Geometric Types</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REV="MADE" HREF="mailto:pgsql-docs@postgresql.org"><LINK REL="HOME" TITLE="PostgreSQL 8.0.11 Documentation" HREF="index.html"><LINK REL="UP" TITLE="Data Types" HREF="datatype.html"><LINK REL="PREVIOUS" TITLE="Boolean Type" HREF="datatype-boolean.html"><LINK REL="NEXT" TITLE="Network Address Types" HREF="datatype-net-types.html"><LINK REL="STYLESHEET" TYPE="text/css" HREF="stylesheet.css"><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"><META NAME="creation" CONTENT="2007-02-02T03:57:22"></HEAD ><BODY CLASS="SECT1" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="5" ALIGN="center" VALIGN="bottom" >PostgreSQL 8.0.11 Documentation</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A HREF="datatype-boolean.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A HREF="datatype.html" >Fast Backward</A ></TD ><TD WIDTH="60%" ALIGN="center" VALIGN="bottom" >Chapter 8. Data Types</TD ><TD WIDTH="10%" ALIGN="right" VALIGN="top" ><A HREF="datatype.html" >Fast Forward</A ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="top" ><A HREF="datatype-net-types.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="DATATYPE-GEOMETRIC" >8.7. Geometric Types</A ></H1 ><P > Geometric data types represent two-dimensional spatial objects. <A HREF="datatype-geometric.html#DATATYPE-GEO-TABLE" >Table 8-16</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 8-16. 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 the 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 ><(x,y),r> (center 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 9.10</A >. </P ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN4985" >8.7.1. Points</A ></H2 ><A NAME="AEN4987" ></A ><P > Points are the fundamental two-dimensional building block for geometric types. Values of type <TT CLASS="TYPE" >point</TT > are specified using the following syntax: </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 ></DIV ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN4998" >8.7.2. Line Segments</A ></H2 ><A NAME="AEN5000" ></A ><A NAME="AEN5002" ></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 the following syntax: </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 the end points of the line segment. </P ></DIV ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN5026" >8.7.3. Boxes</A ></H2 ><A NAME="AEN5028" ></A ><A NAME="AEN5030" ></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 the following syntax: </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 first syntax. The corners are reordered on input to store the upper right corner, then the lower left corner. Other corners of the box can be entered, but the lower left and upper right corners are determined from the input and stored. </P ></DIV ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN5054" >8.7.4. Paths</A ></H2 ><A NAME="AEN5056" ></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 not considered 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 the following syntax: </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. </P ><P > Paths are output using the first syntax. </P ></DIV ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN5087" >8.7.5. Polygons</A ></H2 ><A NAME="AEN5089" ></A ><P > Polygons are represented by lists of points (the vertexes of the polygon). Polygons should probably be considered equivalent 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 the following syntax: </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="AEN5112" >8.7.6. Circles</A ></H2 ><A NAME="AEN5114" ></A ><P > Circles are represented by a center point and a radius. Values of type <TT CLASS="TYPE" >circle</TT > are specified using the following syntax: </P><PRE CLASS="SYNOPSIS" >< ( <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 > <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 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 ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="datatype-boolean.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="datatype-net-types.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Boolean Type</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="datatype.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Network Address Types</TD ></TR ></TABLE ></DIV ></BODY ></HTML >