pgr_dijkstraVia
 Proposed¶
pgr_dijkstraVia
— Route that goes through a list of vertices.
Warning
Proposed functions for next mayor release.
They are not officially in the current release.
They will likely officially be part of the next mayor release:
The functions make use of ANYINTEGER and ANYNUMERICAL
Name might not change. (But still can)
Signature might not change. (But still can)
Functionality might not change. (But still can)
pgTap tests have being done. But might need more.
Documentation might need refinement.
Availability
Version 2.2.0
New proposed function
Description¶
Given a list of vertices and a graph, this function is equivalent to finding the shortest path between \(vertex_i\) and \(vertex_{i+1}\) for all \(i < size\_of(via\;vertices)\).
 Route:
is a sequence of paths.
 Path:
is a section of the route.
Signatures¶
One Via¶
[directed, strict, U_turn_on_edge]
(seq, path_id, path_seq, start_vid, end_vid, node, edge, cost, agg_cost, route_agg_cost)
 Example:
Find the route that visits the vertices \(\{5, 1, 8\}\) in that order on an directed graph.
SELECT * FROM pgr_dijkstraVia(
'SELECT id, source, target, cost, reverse_cost FROM edges order by id',
ARRAY[5, 1, 8]);
seq  path_id  path_seq  start_vid  end_vid  node  edge  cost  agg_cost  route_agg_cost
+++++++++
1  1  1  5  1  5  1  1  0  0
2  1  2  5  1  6  4  1  1  1
3  1  3  5  1  7  7  1  2  2
4  1  4  5  1  3  6  1  3  3
5  1  5  5  1  1  1  0  4  4
6  2  1  1  8  1  6  1  0  4
7  2  2  1  8  3  7  1  1  5
8  2  3  1  8  7  10  1  2  6
9  2  4  1  8  8  2  0  3  7
(9 rows)
Parameters¶
Parameter 
Type 
Default 
Description 


SQL query as described. 

via vertices 

Array of ordered vertices identifiers that are going to be visited. 
Where:
 ANYINTEGER:
SMALLINT, INTEGER, BIGINT
Optional parameters¶
Column 
Type 
Default 
Description 





Via optional parameters¶
Parameter 
Type 
Default 
Description 









Inner Queries¶
Edges SQL¶
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¶
Column 
Type 
Description 



Sequential value starting from 1. 


Identifier of a path. Has value 1 for the first path. 


Relative position in the path. Has value 1 for the beginning of a path. 


Identifier of the starting vertex of the path. 


Identifier of the ending vertex of the path. 


Identifier of the node in the path from 


Identifier of the edge used to go from



Cost to traverse from 


Aggregate cost from 


Total cost from 
Additional Examples¶
All this examples are about the route that visits the vertices \(\{5, 7, 1, 8, 15\}\) in that order on a directed graph.
The main query¶
SELECT * FROM pgr_dijkstraVia(
'SELECT id, source, target, cost, reverse_cost FROM edges order by id',
ARRAY[5, 7, 1, 8, 15]);
seq  path_id  path_seq  start_vid  end_vid  node  edge  cost  agg_cost  route_agg_cost
+++++++++
1  1  1  5  7  5  1  1  0  0
2  1  2  5  7  6  4  1  1  1
3  1  3  5  7  7  1  0  2  2
4  2  1  7  1  7  7  1  0  2
5  2  2  7  1  3  6  1  1  3
6  2  3  7  1  1  1  0  2  4
7  3  1  1  8  1  6  1  0  4
8  3  2  1  8  3  7  1  1  5
9  3  3  1  8  7  10  1  2  6
10  3  4  1  8  8  1  0  3  7
11  4  1  8  15  8  12  1  0  7
12  4  2  8  15  12  13  1  1  8
13  4  3  8  15  17  15  1  2  9
14  4  4  8  15  16  16  1  3  10
15  4  5  8  15  15  2  0  4  11
(15 rows)
Aggregate cost of the third path.¶
SELECT agg_cost FROM pgr_dijkstraVia(
'SELECT id, source, target, cost, reverse_cost FROM edges order by id',
ARRAY[5, 7, 1, 8, 15])
WHERE path_id = 3 AND edge <0;
agg_cost

3
(1 row)
Route’s aggregate cost of the route at the end of the third path.¶
SELECT route_agg_cost FROM pgr_dijkstraVia(
'SELECT id, source, target, cost, reverse_cost FROM edges order by id',
ARRAY[5, 7, 1, 8, 15])
WHERE path_id = 3 AND edge < 0;
route_agg_cost

7
(1 row)
Nodes visited in the route.¶
SELECT row_number() over () as node_seq, node
FROM pgr_dijkstraVia(
'SELECT id, source, target, cost, reverse_cost FROM edges order by id',
ARRAY[5, 7, 1, 8, 15])
WHERE edge <> 1 ORDER BY seq;
node_seq  node
+
1  5
2  6
3  7
4  3
5  1
6  3
7  7
8  8
9  12
10  17
11  16
12  15
(12 rows)
The aggregate costs of the route when the visited vertices are reached.¶
SELECT path_id, route_agg_cost FROM pgr_dijkstraVia(
'SELECT id, source, target, cost, reverse_cost FROM edges order by id',
ARRAY[5, 7, 1, 8, 15])
WHERE edge < 0;
path_id  route_agg_cost
+
1  2
2  4
3  7
4  11
(4 rows)
Status of “passes in front” or “visits” of the nodes.¶
SELECT seq, route_agg_cost, node, agg_cost ,
CASE WHEN edge = 1 THEN 'visits'
ELSE 'passes in front'
END as status
FROM pgr_dijkstraVia(
'SELECT id, source, target, cost, reverse_cost FROM edges order by id',
ARRAY[5, 7, 1, 8, 15])
WHERE agg_cost <> 0 or seq = 1;
seq  route_agg_cost  node  agg_cost  status
++++
1  0  5  0  passes in front
2  1  6  1  passes in front
3  2  7  2  visits
5  3  3  1  passes in front
6  4  1  2  visits
8  5  3  1  passes in front
9  6  7  2  passes in front
10  7  8  3  visits
12  8  12  1  passes in front
13  9  17  2  passes in front
14  10  16  3  passes in front
15  11  15  4  passes in front
(12 rows)
See Also¶
Sample Data network.
Indices and tables