polygon

closed geometric path on a plane

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Catalog name: pg_catalog.polygon
Type OID: 604
Type kind: Base type
Declared length: Variable length (varlena)
Storage strategy: extended
Input function: poly_in
Output function: poly_out
Documented declaration: polygon
Storage Size: 40+16n bytes
Manual description: Polygon (similar to closed path)
Representation: ((x1,y1),...)
aliases: 未知
coverage: source inventory; exact declared input types for operator classes
manual documentation: dedicated family chapter
manual path: datatype-geometric.html
ranges: 未知
signature: polygon

版本定义 PG 18

8.8. Geometric Types

Geometric data types represent two-dimensional spatial objects. Table 8.20 shows the geometric types available in PostgreSQL.

Table 8.20. Geometric Types

Name	Storage Size	Description	Representation
`point`	16 bytes	Point on a plane	(x,y)
`line`	24 bytes	Infinite line	{A,B,C}
`lseg`	32 bytes	Finite line segment	[(x1,y1),(x2,y2)]
`box`	32 bytes	Rectangular box	(x1,y1),(x2,y2)
`path`	16+16n bytes	Closed path (similar to polygon)	((x1,y1),...)
`path`	16+16n bytes	Open path	[(x1,y1),...]
`polygon`	40+16n bytes	Polygon (similar to closed path)	((x1,y1),...)
`circle`	24 bytes	Circle	<(x,y),r> (center point and radius)

In all these types, the individual coordinates are stored as double precision (float8) numbers.

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 Section 9.11.

8.8.1. Points

Points are the fundamental two-dimensional building block for geometric types. Values of type point are specified using either of the following syntaxes:

( x , y )
  x , y

where x and y are the respective coordinates, as floating-point numbers.

Points are output using the first syntax.

8.8.2. Lines

Lines are represented by the linear equation Ax + By + C = 0, where A and B are not both zero. Values of type line are input and output in the following form:

{ A, B, C }

Alternatively, any of the following forms can be used for input:

[ ( x1 , y1 ) , ( x2 , y2 ) ]
( ( x1 , y1 ) , ( x2 , y2 ) )
  ( x1 , y1 ) , ( x2 , y2 )
    x1 , y1   ,   x2 , y2

where (x1,y1) and (x2,y2) are two different points on the line.

8.8.3. Line Segments

Line segments are represented by pairs of points that are the endpoints of the segment. Values of type lseg are specified using any of the following syntaxes:

[ ( x1 , y1 ) , ( x2 , y2 ) ]
( ( x1 , y1 ) , ( x2 , y2 ) )
  ( x1 , y1 ) , ( x2 , y2 )
    x1 , y1   ,   x2 , y2

where (x1,y1) and (x2,y2) are the end points of the line segment.

Line segments are output using the first syntax.

8.8.4. Boxes

Boxes are represented by pairs of points that are opposite corners of the box. Values of type box are specified using any of the following syntaxes:

( ( x1 , y1 ) , ( x2 , y2 ) )
  ( x1 , y1 ) , ( x2 , y2 )
    x1 , y1   ,   x2 , y2

where (x1,y1) and (x2,y2) are any two opposite corners of the box.

Boxes are output using the second syntax.

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.

8.8.5. Paths

Paths are represented by lists of connected points. Paths can be open, where the first and last points in the list are considered not connected, or closed, where the first and last points are considered connected.

Values of type path are specified using any of the following syntaxes:

[ ( x1 , y1 ) , ... , ( xn , yn ) ]
( ( x1 , y1 ) , ... , ( xn , yn ) )
  ( x1 , y1 ) , ... , ( xn , yn )
  ( x1 , y1   , ... ,   xn , yn )
    x1 , y1   , ... ,   xn , yn

where the points are the end points of the line segments comprising the path. Square brackets ([]) indicate an open path, while parentheses (()) indicate a closed path. When the outermost parentheses are omitted, as in the third through fifth syntaxes, a closed path is assumed.

Paths are output using the first or second syntax, as appropriate.

8.8.6. Polygons

Polygons are represented by lists of points (the vertices of the polygon). Polygons are very similar to closed paths; the essential semantic difference is that a polygon is considered to include the area within it, while a path is not.

An important implementation difference between polygons and paths is that the stored representation of a polygon includes its smallest bounding box. This speeds up certain search operations, although computing the bounding box adds overhead while constructing new polygons.

Values of type polygon are specified using any of the following syntaxes:

( ( x1 , y1 ) , ... , ( xn , yn ) )
  ( x1 , y1 ) , ... , ( xn , yn )
  ( x1 , y1   , ... ,   xn , yn )
    x1 , y1   , ... ,   xn , yn

where the points are the end points of the line segments comprising the boundary of the polygon.

Polygons are output using the first syntax.

8.8.7. Circles

Circles are represented by a center point and radius. Values of type circle are specified using any of the following syntaxes:

< ( x , y ) , r >
( ( x , y ) , r )
  ( x , y ) , r
    x , y   , r

where (x,y) is the center point and r is the radius of the circle.

Circles are output using the first syntax.

比较版本

完整来源事实

casts

map[castcontext:a castfunc:polygon(path) castmethod:f castsource:path casttarget:polygon], map[castcontext:a castfunc:polygon(box) castmethod:f castsource:box casttarget:polygon], map[castcontext:e castfunc:point(polygon) castmethod:f castsource:polygon casttarget:point], map[castcontext:a castfunc:path castmethod:f castsource:polygon casttarget:path], map[castcontext:e castfunc:box(polygon) castmethod:f castsource:polygon casttarget:box], map[castcontext:e castfunc:circle(polygon) castmethod:f castsource:polygon casttarget:circle], map[castcontext:e castfunc:polygon(circle) castmethod:f castsource:circle casttarget:polygon]

catalog

{"array_type_name":"_polygon","array_type_oid":"1027","descr":"geometric polygon, format '(point1,...)'","oid":"604","typacl":"_null_","typalign":"d","typanalyze":"-","typarray":"0","typbasetype":"0","typbyval":"f","typcategory":"G","typcollation":"0","typdefault":"_null_","typdefaultbin":"_null_","typdelim":"','","typelem":"0","typinput":"poly_in","typisdefined":"t","typispreferred":"f","typlen":"-1","typmodin":"-","typmodout":"-","typname":"polygon","typnamespace":"pg_catalog","typndims":"0","typnotnull":"f","typoutput":"poly_out","typowner":"POSTGRES","typreceive":"poly_recv","typrelid":"0","typsend":"poly_send","typstorage":"x","typsubscript":"-","typtype":"b","typtypmod":"-1"}

operator classes

map[opcdefault:t opcfamily:gist/poly_ops opcintype:polygon opckeytype:box opcmethod:gist opcname:poly_ops opcnamespace:pg_catalog opcowner:POSTGRES], map[opcdefault:t opcfamily:spgist/poly_ops opcintype:polygon opckeytype:box opcmethod:spgist opcname:poly_ops opcnamespace:pg_catalog opcowner:POSTGRES]

operators

map[descr:is left of oid:485 oprcanhash:f oprcanmerge:f oprcode:poly_left oprcom:0 oprjoin:positionjoinsel oprkind:b oprleft:polygon oprname:<< oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:positionsel oprresult:bool oprright:polygon], map[descr:overlaps or is left of oid:486 oprcanhash:f oprcanmerge:f oprcode:poly_overleft oprcom:0 oprjoin:positionjoinsel oprkind:b oprleft:polygon oprname:&< oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:positionsel oprresult:bool oprright:polygon], map[descr:overlaps or is right of oid:487 oprcanhash:f oprcanmerge:f oprcode:poly_overright oprcom:0 oprjoin:positionjoinsel oprkind:b oprleft:polygon oprname:&> oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:positionsel oprresult:bool oprright:polygon], map[descr:is right of oid:488 oprcanhash:f oprcanmerge:f oprcode:poly_right oprcom:0 oprjoin:positionjoinsel oprkind:b oprleft:polygon oprname:>> oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:positionsel oprresult:bool oprright:polygon], map[descr:is contained by oid:489 oprcanhash:f oprcanmerge:f oprcode:poly_contained oprcom:@>(polygon,polygon) oprjoin:contjoinsel oprkind:b oprleft:polygon oprname:<@ oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:contsel oprresult:bool oprright:polygon], map[descr:contains oid:490 oprcanhash:f oprcanmerge:f oprcode:poly_contain oprcom:<@(polygon,polygon) oprjoin:contjoinsel oprkind:b oprleft:polygon oprname:@> oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:contsel oprresult:bool oprright:polygon], map[descr:same as oid:491 oprcanhash:f oprcanmerge:f oprcode:poly_same oprcom:~=(polygon,polygon) oprjoin:eqjoinsel oprkind:b oprleft:polygon oprname:~= oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:eqsel oprresult:bool oprright:polygon], map[descr:overlaps oid:492 oprcanhash:f oprcanmerge:f oprcode:poly_overlap oprcom:&&(polygon,polygon) oprjoin:areajoinsel oprkind:b oprleft:polygon oprname:&& oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:areasel oprresult:bool oprright:polygon], map[descr:distance between oid:712 oprcanhash:f oprcanmerge:f oprcode:poly_distance oprcom:<->(polygon,polygon) oprjoin:- oprkind:b oprleft:polygon oprname:<-> oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:float8 oprright:polygon], map[descr:is contained by oid:756 oprcanhash:f oprcanmerge:f oprcode:pt_contained_poly oprcom:@>(polygon,point) oprjoin:contjoinsel oprkind:b oprleft:point oprname:<@ oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:contsel oprresult:bool oprright:polygon], map[descr:contains oid:757 oprcanhash:f oprcanmerge:f oprcode:poly_contain_pt oprcom:<@(point,polygon) oprjoin:contjoinsel oprkind:b oprleft:polygon oprname:@> oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:contsel oprresult:bool oprright:point], map[descr:center of oid:971 oprcanhash:f oprcanmerge:f oprcode:poly_center oprcom:0 oprjoin:- oprkind:l oprleft:0 oprname:@@ oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:point oprright:polygon], map[descr:number of points oid:1521 oprcanhash:f oprcanmerge:f oprcode:poly_npoints oprcom:0 oprjoin:- oprkind:l oprleft:0 oprname:# oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:int4 oprright:polygon], map[descr:distance between oid:3276 oprcanhash:f oprcanmerge:f oprcode:dist_ppoly oprcom:<->(polygon,point) oprjoin:- oprkind:b oprleft:point oprname:<-> oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:float8 oprright:polygon], map[descr:distance between oid:3289 oprcanhash:f oprcanmerge:f oprcode:dist_polyp oprcom:<->(point,polygon) oprjoin:- oprkind:b oprleft:polygon oprname:<-> oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:float8 oprright:point], map[descr:distance between oid:1523 oprcanhash:f oprcanmerge:f oprcode:dist_cpoly oprcom:<->(polygon,circle) oprjoin:- oprkind:b oprleft:circle oprname:<-> oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:float8 oprright:polygon], map[descr:distance between oid:1383 oprcanhash:f oprcanmerge:f oprcode:dist_polyc oprcom:<->(circle,polygon) oprjoin:- oprkind:b oprleft:polygon oprname:<-> oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:float8 oprright:circle], map[descr:is below oid:2574 oprcanhash:f oprcanmerge:f oprcode:poly_below oprcom:0 oprjoin:positionjoinsel oprkind:b oprleft:polygon oprname:<<| oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:positionsel oprresult:bool oprright:polygon], map[descr:overlaps or is below oid:2575 oprcanhash:f oprcanmerge:f oprcode:poly_overbelow oprcom:0 oprjoin:positionjoinsel oprkind:b oprleft:polygon oprname:&<| oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:positionsel oprresult:bool oprright:polygon], map[descr:overlaps or is above oid:2576 oprcanhash:f oprcanmerge:f oprcode:poly_overabove oprcom:0 oprjoin:positionjoinsel oprkind:b oprleft:polygon oprname:|&> oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:positionsel oprresult:bool oprright:polygon], map[descr:is above oid:2577 oprcanhash:f oprcanmerge:f oprcode:poly_above oprcom:0 oprjoin:positionjoinsel oprkind:b oprleft:polygon oprname:|>> oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:positionsel oprresult:bool oprright:polygon]

来源引用

完整定义与证据 JSON

定义来源

center · PostgreSQL 18 · 555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f

正文语言: en · 555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f