pgr_chinesePostman
 Experimental¶
pgr_chinesePostman
— Calculates the shortest circuit path which contains
every edge in a directed graph and starts and ends on the same vertex.
Warning
Possible server crash
These functions might create a server crash
Warning
Experimental functions
They are not officially of the current release.
They likely will not be officially be part of the next release:
The functions might not make use of ANYINTEGER and ANYNUMERICAL
Name might change.
Signature might change.
Functionality might change.
pgTap tests might be missing.
Might need c/c++ coding.
May lack documentation.
Documentation if any might need to be rewritten.
Documentation examples might need to be automatically generated.
Might need a lot of feedback from the comunity.
Might depend on a proposed function of pgRouting
Might depend on a deprecated function of pgRouting
Availability
Version 3.0.0
New experimental signature
Description¶
The main characteristics are:
Process is done only on edges with positive costs.
Running time: \(O(E * (E + V * logV))\)
Graph must be connected.
Returns
EMPTY SET
on a disconnected graph
Signatures¶
pgr_chinesePostman(Edges SQL) RETURNS SET OF (seq, node, edge, cost, agg_cost) OR EMPTY SET
 Example:
SELECT * FROM pgr_chinesePostman(
'SELECT id, source, target, cost, reverse_cost
FROM edges WHERE id < 17');
seq  node  edge  cost  agg_cost
++++
1  1  6  1  0
2  3  7  1  1
3  7  4  1  2
4  6  4  1  3
5  7  8  1  4
6  11  8  1  5
7  7  10  1  6
8  8  12  1  7
9  12  13  1  8
10  17  15  1  9
11  16  15  1  10
12  17  15  1  11
13  16  16  1  12
14  15  16  1  13
15  16  9  1  14
16  11  11  1  15
17  12  13  1  16
18  17  15  1  17
19  16  16  1  18
20  15  3  1  19
21  10  5  1  20
22  11  9  1  21
23  16  16  1  22
24  15  3  1  23
25  10  2  1  24
26  6  1  1  25
27  5  1  1  26
28  6  4  1  27
29  7  10  1  28
30  8  14  1  29
31  9  14  1  30
32  8  10  1  31
33  7  7  1  32
34  3  6  1  33
35  1  1  0  34
(35 rows)
Parameters¶
Parameter 
Type 
Description 


Edges SQL as described below. 
Inner Queries¶
Edges SQL¶
An Edges SQL that represents a directed graph with the following columns
Column 
Type 
Default 
Description 


ANYINTEGER 
Identifier of the edge. 


ANYINTEGER 
Identifier of the first end point vertex of the edge. 


ANYINTEGER 
Identifier of the second end point vertex of the edge. 


ANYNUMERICAL 
Weight of the edge ( 


ANYNUMERICAL 
1 
Weight of the edge (

Where:
 ANYINTEGER:
SMALLINT
,INTEGER
,BIGINT
 ANYNUMERICAL:
SMALLINT
,INTEGER
,BIGINT
,REAL
,FLOAT
Result Columns¶
Returns set of (seq, node, edge, cost, agg_cost)
Column 
Type 
Description 



Sequential value starting from 


Identifier of the node in the path from 


Identifier of the edge used to go from 


Cost to traverse from 


Aggregate cost from 
See Also¶
Indices and tables