path

geometric path on a plane

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Catalog name: pg_catalog.path
Type OID: 602
Type kind: Base type
Declared length: Variable length (varlena)
Storage strategy: extended
Input function: path_in
Output function: path_out
Documented declaration: path
Storage Size: 16+16n bytes
Manual description: Closed path (similar to polygon)
Representation: ((x1,y1),...)
Manual description: Open path
aliases: 未知
casts: map[castcontext:a castfunc:polygon(path) castmethod:f castsource:path casttarget:polygon], map[castcontext:a castfunc:path castmethod:f castsource:polygon casttarget:path]
coverage: source inventory; exact declared input types for operator classes
manual documentation: dedicated family chapter
manual path: datatype-geometric.html
operator classes: 未知
ranges: 未知
signature: path

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

Representation

[(x1,y1),...]

catalog

{"array_type_name":"_path","array_type_oid":"1019","descr":"geometric path, format '(point1,...)'","oid":"602","typacl":"_null_","typalign":"d","typanalyze":"-","typarray":"0","typbasetype":"0","typbyval":"f","typcategory":"G","typcollation":"0","typdefault":"_null_","typdefaultbin":"_null_","typdelim":"','","typelem":"0","typinput":"path_in","typisdefined":"t","typispreferred":"f","typlen":"-1","typmodin":"-","typmodout":"-","typname":"path","typnamespace":"pg_catalog","typndims":"0","typnotnull":"f","typoutput":"path_out","typowner":"POSTGRES","typreceive":"path_recv","typrelid":"0","typsend":"path_send","typstorage":"x","typsubscript":"-","typtype":"b","typtypmod":"-1"}

operators

map[descr:point within closed path, or point on open path oid:512 oprcanhash:f oprcanmerge:f oprcode:on_ppath oprcom:@>(path,point) oprjoin:- oprkind:b oprleft:point oprname:<@ oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:bool oprright:path], map[descr:distance between oid:618 oprcanhash:f oprcanmerge:f oprcode:dist_ppath oprcom:<->(path,point) oprjoin:- oprkind:b oprleft:point oprname:<-> oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:float8 oprright:path], map[descr:distance between oid:784 oprcanhash:f oprcanmerge:f oprcode:dist_pathp oprcom:<->(point,path) oprjoin:- oprkind:b oprleft:path oprname:<-> oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:float8 oprright:point], map[descr:distance between oid:707 oprcanhash:f oprcanmerge:f oprcode:path_distance oprcom:<->(path,path) oprjoin:- oprkind:b oprleft:path oprname:<-> oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:float8 oprright:path], map[descr:concatenate oid:735 oprcanhash:f oprcanmerge:f oprcode:path_add oprcom:+(path,path) oprjoin:- oprkind:b oprleft:path oprname:+ oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:path oprright:path], map[descr:add (translate path) oid:736 oprcanhash:f oprcanmerge:f oprcode:path_add_pt oprcom:0 oprjoin:- oprkind:b oprleft:path oprname:+ oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:path oprright:point], map[descr:subtract (translate path) oid:737 oprcanhash:f oprcanmerge:f oprcode:path_sub_pt oprcom:0 oprjoin:- oprkind:b oprleft:path oprname:- oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:path oprright:point], map[descr:multiply (rotate/scale path) oid:738 oprcanhash:f oprcanmerge:f oprcode:path_mul_pt oprcom:0 oprjoin:- oprkind:b oprleft:path oprname:* oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:path oprright:point], map[descr:divide (rotate/scale path) oid:739 oprcanhash:f oprcanmerge:f oprcode:path_div_pt oprcom:0 oprjoin:- oprkind:b oprleft:path oprname:/ oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:path oprright:point], map[descr:contains oid:755 oprcanhash:f oprcanmerge:f oprcode:path_contain_pt oprcom:<@(point,path) oprjoin:- oprkind:b oprleft:path oprname:@> oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:bool oprright:point], map[descr:equal oid:792 oprcanhash:f oprcanmerge:f oprcode:path_n_eq oprcom:=(path,path) oprjoin:eqjoinsel oprkind:b oprleft:path oprname:= oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:eqsel oprresult:bool oprright:path], map[descr:less than oid:793 oprcanhash:f oprcanmerge:f oprcode:path_n_lt oprcom:>(path,path) oprjoin:- oprkind:b oprleft:path oprname:< oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:bool oprright:path], map[descr:greater than oid:794 oprcanhash:f oprcanmerge:f oprcode:path_n_gt oprcom:<(path,path) oprjoin:- oprkind:b oprleft:path oprname:> oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:bool oprright:path], map[descr:less than or equal oid:795 oprcanhash:f oprcanmerge:f oprcode:path_n_le oprcom:>=(path,path) oprjoin:- oprkind:b oprleft:path oprname:<= oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:bool oprright:path], map[descr:greater than or equal oid:796 oprcanhash:f oprcanmerge:f oprcode:path_n_ge oprcom:<=(path,path) oprjoin:- oprkind:b oprleft:path oprname:>= oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:bool oprright:path], map[descr:number of points oid:797 oprcanhash:f oprcanmerge:f oprcode:path_npoints oprcom:0 oprjoin:- oprkind:l oprleft:0 oprname:# oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:int4 oprright:path], map[descr:intersect oid:798 oprcanhash:f oprcanmerge:f oprcode:path_inter oprcom:0 oprjoin:- oprkind:b oprleft:path oprname:?# oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:bool oprright:path], map[descr:sum of path segment lengths oid:799 oprcanhash:f oprcanmerge:f oprcode:path_length oprcom:0 oprjoin:- oprkind:l oprleft:0 oprname:@-@ oprnamespace:pg_catalog oprnegate:0 oprowner:POSTGRES oprrest:- oprresult:float8 oprright:path]

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