pgr_dijkstra - Shortest Path Dijkstra¶
pgr_dijkstra — Returns the shortest path(s) using Dijkstra algorithm.
In particular, the Dijkstra algorithm implemented by Boost.Graph.
Boost Graph Inside
Synopsis¶
Dijkstra’s algorithm, conceived by Dutch computer scientist Edsger Dijkstra in 1956.
It is a graph search algorithm that solves the shortest path problem for
a graph with non-negative edge path costs, producing a shortest path from
a starting vertex (start_vid) to an ending vertex (end_vid).
This implementation can be used with a directed graph and an undirected graph.
Signatures¶
Minimal signature
The minimal signature is for a directed graph from one start_vid to one end_vid:
pgr_dijkstra(text edges_sql, bigint start_vid, bigint end_vid)
RETURNS SET OF (seq, path_seq, node, edge, cost, agg_cost) or EMPTY SET
Dijkstra 1 to 1
- This signature performs a Dijkstra from one
start_vidto oneend_vid: - on a directed graph when
directedflag is missing or is set totrue. - on an undirected graph when
directedflag is set tofalse.
- on a directed graph when
pgr_dijkstra(text edges_sql, bigint start_vid, bigint end_vid,
boolean directed:=true);
RETURNS SET OF (seq, path_seq, node, edge, cost, agg_cost) or EMPTY SET
Dijkstra many to 1:
pgr_dijkstra(text edges_sql, array[ANY_INTEGER] start_vids, bigint end_vid,
boolean directed:=true);
RETURNS SET OF (seq, path_seq, start_vid, node, edge, cost, agg_cost) or EMPTY SET
- This signature performs a Dijkstra from each
start_vidinstart_vidsto oneend_vid: - on a directed graph when
directedflag is missing or is set totrue. - on an undirected graph when
directedflag is set tofalse.
- on a directed graph when
Using this signature, will load once the graph and perform several one to one Dijkstra where the ending vertex is fixed. The result is the union of the results of the one to one dijkstra.
The extra start_vid in the result is used to distinguish to which path it belongs.
Dijkstra 1 to many:
pgr_dijkstra(text edges_sql, bigint start_vid, array[ANY_INTEGER] end_vids,
boolean directed:=true);
RETURNS SET OF (seq, path_seq, end_vid, node, edge, cost, agg_cost) or EMPTY SET
- This signature performs a Dijkstra from one
start_vidto eachend_vidinend_vids: - on a directed graph when
directedflag is missing or is set totrue. - on an undirected graph when
directedflag is set tofalse.
- on a directed graph when
Using this signature, will load once the graph and perform several 1 to 1 Dijkstra where the starting vertex is fixed. The result is the union of the results of the one to one dijkstra.
The extra end_vid in the result is used to distinguish to which path it belongs.
Dijkstra many to many:
pgr_dijkstra(text edges_sql, array[ANY_INTEGER] start_vids, array[ANY_INTEGER] end_vids,
boolean directed:=true);
RETURNS SET OF (seq, path_seq, start_vid, end_vid, node, edge, cost, agg_cost) or EMPTY SET
- This signature performs a Dijkstra from each
start_vidinstart_vidsto eachend_vidinend_vids: - on a directed graph when
directedflag is missing or is set totrue. - on an undirected graph when
directedflag is set tofalse.
- on a directed graph when
Using this signature, will load once the graph and perform all combinations for starting vertices and ending vertices.
The extra start_vid and end_vid in the result is used to distinguish to which path it belongs.
Description of the Signatures¶
Description of the SQL query¶
| edges_sql: | an SQL query, which should return a set of rows with the following columns:
|
|---|
Where:
| ANY-INTEGER: | smallint, int, bigint |
|---|---|
| ANY-NUMERICAL: | smallint, int, bigint, real, float |
For example:
SELECT id, source, target, cost, reverse_cost from edge_table where geom && ST_Expand(ST_SetSRID(ST_Point(45, 34), 4326), 0.1)
Description of the parameters of the signatures¶
| sql: | SQL query as decribed above. |
|---|---|
| start_vid: | BIGINT identifier of the starting vertex of the path. |
| start_vids: | array[ANY-INTEGER] array of identifiers of starting vertices. |
| end_vid: | BIGINT identifier of the ending vertex of the path. |
| end_vids: | array[ANY-INTEGER] array of identifiers of ending vertices. |
| directed: | boolean (optional). When false the graph is considered as Undirected. Default is true which considers the graph as Directed. |
Description of the return values¶
Returns set of (seq [, start_vid] [, end_vid] , node, edge, cost, agg_cost)
| seq: | INT isequential value starting from 1. |
|---|---|
| path_seq: | INT relative position in the path. Has value 1 for the begining of a path. |
| start_vid: | BIGINT id of the starting vertex. Used when multiple starting vetrices are in the query. |
| end_vid: | BIGINT id of the ending vertex. Used when multiple ending vertices are in the query. |
| node: | BIGINT id of the node in the path from start_vid to end_v. |
| edge: | BIGINT id of the edge used to go from node to the next node in the path sequence. -1 for the last node of the path. |
| cost: | FLOAT cost to traverse from node using edge to the next node in the path sequence. |
| agg_cost: | FLOAT total cost from start_v to node. |
Examples¶
The examples of this section are based on the Sample Data network.
The examples include combinations from starting vertices 2 and 11 to ending vertices 3 and 5 in a directed and undirected graph with and with out reverse_cost.
Examples for queries marked as directed with cost and reverse_cost columns¶
The examples in this section use the following Graph 1: Directed, with cost and reverse cost
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
2, 3
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
1 | 1 | 2 | 4 | 1 | 0
2 | 2 | 5 | 8 | 1 | 1
3 | 3 | 6 | 9 | 1 | 2
4 | 4 | 9 | 16 | 1 | 3
5 | 5 | 4 | 3 | 1 | 4
6 | 6 | 3 | -1 | 0 | 5
(6 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
2, 5
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
1 | 1 | 2 | 4 | 1 | 0
2 | 2 | 5 | -1 | 0 | 1
(2 rows)
When you pass an array we get a combined result:
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
2, array[3,5]
);
seq | path_seq | end_vid | node | edge | cost | agg_cost
-----+----------+---------+------+------+------+----------
1 | 1 | 3 | 2 | 4 | 1 | 0
2 | 2 | 3 | 5 | 8 | 1 | 1
3 | 3 | 3 | 6 | 9 | 1 | 2
4 | 4 | 3 | 9 | 16 | 1 | 3
5 | 5 | 3 | 4 | 3 | 1 | 4
6 | 6 | 3 | 3 | -1 | 0 | 5
7 | 1 | 5 | 2 | 4 | 1 | 0
8 | 2 | 5 | 5 | -1 | 0 | 1
(8 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
11, 3
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
1 | 1 | 11 | 13 | 1 | 0
2 | 2 | 12 | 15 | 1 | 1
3 | 3 | 9 | 16 | 1 | 2
4 | 4 | 4 | 3 | 1 | 3
5 | 5 | 3 | -1 | 0 | 4
(5 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
11, 5
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
1 | 1 | 11 | 13 | 1 | 0
2 | 2 | 12 | 15 | 1 | 1
3 | 3 | 9 | 9 | 1 | 2
4 | 4 | 6 | 8 | 1 | 3
5 | 5 | 5 | -1 | 0 | 4
(5 rows)
Some other combinations.
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
array[2,11], 5
);
seq | path_seq | start_vid | node | edge | cost | agg_cost
-----+----------+---------+------+------+------+----------
1 | 1 | 2 | 2 | 4 | 1 | 0
2 | 2 | 2 | 5 | -1 | 0 | 1
3 | 1 | 11 | 11 | 13 | 1 | 0
4 | 2 | 11 | 12 | 15 | 1 | 1
5 | 3 | 11 | 9 | 9 | 1 | 2
6 | 4 | 11 | 6 | 8 | 1 | 3
7 | 5 | 11 | 5 | -1 | 0 | 4
(7 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
array[2, 11], array[3,5]
);
seq | path_seq | start_vid | end_vid | node | edge | cost | agg_cost
-----+----------+---------+-------+------+------+------+----------
1 | 1 | 2 | 3 | 2 | 4 | 1 | 0
2 | 2 | 2 | 3 | 5 | 8 | 1 | 1
3 | 3 | 2 | 3 | 6 | 9 | 1 | 2
4 | 4 | 2 | 3 | 9 | 16 | 1 | 3
5 | 5 | 2 | 3 | 4 | 3 | 1 | 4
6 | 6 | 2 | 3 | 3 | -1 | 0 | 5
7 | 1 | 2 | 5 | 2 | 4 | 1 | 0
8 | 2 | 2 | 5 | 5 | -1 | 0 | 1
9 | 1 | 11 | 3 | 11 | 13 | 1 | 0
10 | 2 | 11 | 3 | 12 | 15 | 1 | 1
11 | 3 | 11 | 3 | 9 | 16 | 1 | 2
12 | 4 | 11 | 3 | 4 | 3 | 1 | 3
13 | 5 | 11 | 3 | 3 | -1 | 0 | 4
14 | 1 | 11 | 5 | 11 | 13 | 1 | 0
15 | 2 | 11 | 5 | 12 | 15 | 1 | 1
16 | 3 | 11 | 5 | 9 | 9 | 1 | 2
17 | 4 | 11 | 5 | 6 | 8 | 1 | 3
18 | 5 | 11 | 5 | 5 | -1 | 0 | 4
(18 rows)
Examples for queries marked as undirected with cost and reverse_cost columns¶
The examples in this section use the following Graph 2: Undirected, with cost and reverse cost
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
2, 3,
false
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
1 | 1 | 2 | 2 | 1 | 0
2 | 2 | 3 | -1 | 0 | 1
(2 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
2, 5,
false
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
1 | 1 | 2 | 4 | 1 | 0
2 | 2 | 5 | -1 | 0 | 1
(2 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
11, 3,
false
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
1 | 1 | 11 | 11 | 1 | 0
2 | 2 | 6 | 5 | 1 | 1
3 | 3 | 3 | -1 | 0 | 2
(3 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
11, 5,
false
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
1 | 1 | 11 | 11 | 1 | 0
2 | 2 | 6 | 8 | 1 | 1
3 | 3 | 5 | -1 | 0 | 2
(3 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
array[2,11], 5,
false
);
seq | path_seq | start_vid | node | edge | cost | agg_cost
-----+----------+---------+------+------+------+----------
1 | 1 | 2 | 2 | 4 | 1 | 0
2 | 2 | 2 | 5 | -1 | 0 | 1
3 | 1 | 11 | 11 | 11 | 1 | 0
4 | 2 | 11 | 6 | 8 | 1 | 1
5 | 3 | 11 | 5 | -1 | 0 | 2
(5 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
2, array[3,5],
false
);
seq | path_seq | end_vid | node | edge | cost | agg_cost
-----+----------+-------+------+------+------+----------
1 | 1 | 3 | 2 | 2 | 1 | 0
2 | 2 | 3 | 3 | -1 | 0 | 1
3 | 1 | 5 | 2 | 4 | 1 | 0
4 | 2 | 5 | 5 | -1 | 0 | 1
(4 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
array[2, 11], array[3,5],
false
);
seq | path_seq | start_vid | end_vid | node | edge | cost | agg_cost
-----+----------+---------+-------+------+------+------+----------
1 | 1 | 2 | 3 | 2 | 2 | 1 | 0
2 | 2 | 2 | 3 | 3 | -1 | 0 | 1
3 | 1 | 2 | 5 | 2 | 4 | 1 | 0
4 | 2 | 2 | 5 | 5 | -1 | 0 | 1
5 | 1 | 11 | 3 | 11 | 11 | 1 | 0
6 | 2 | 11 | 3 | 6 | 5 | 1 | 1
7 | 3 | 11 | 3 | 3 | -1 | 0 | 2
8 | 1 | 11 | 5 | 11 | 11 | 1 | 0
9 | 2 | 11 | 5 | 6 | 8 | 1 | 1
10 | 3 | 11 | 5 | 5 | -1 | 0 | 2
(10 rows)
Examples for queries marked as directed with cost column¶
The examples in this section use the following Graph 3: Directed, with cost
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost FROM edge_table',
2, 3
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
(0 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost FROM edge_table',
2, 5
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
1 | 1 | 2 | 4 | 1 | 0
2 | 2 | 5 | -1 | 0 | 1
(2 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost FROM edge_table',
11, 3
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
(0 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost FROM edge_table',
11, 5
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
(0 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost FROM edge_table',
array[2,11], 5
);
seq | path_seq | start_vid | node | edge | cost | agg_cost
-----+----------+---------+------+------+------+----------
1 | 1 | 2 | 2 | 4 | 1 | 0
2 | 2 | 2 | 5 | -1 | 0 | 1
(2 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost FROM edge_table',
2, array[3,5]
);
seq | path_seq | end_vid | node | edge | cost | agg_cost
-----+----------+-------+------+------+------+----------
1 | 1 | 5 | 2 | 4 | 1 | 0
2 | 2 | 5 | 5 | -1 | 0 | 1
(2 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost FROM edge_table',
array[2, 11], array[3,5]
);
seq | path_seq | start_vid | end_vid | node | edge | cost | agg_cost
-----+----------+---------+-------+------+------+------+----------
1 | 1 | 2 | 5 | 2 | 4 | 1 | 0
2 | 2 | 2 | 5 | 5 | -1 | 0 | 1
(2 rows)
Examples for queries marked as undirected with cost column¶
The examples in this section use the following Graph 4: Undirected, with cost
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost FROM edge_table',
2, 3,
false
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
1 | 1 | 2 | 4 | 1 | 0
2 | 2 | 5 | 8 | 1 | 1
3 | 3 | 6 | 5 | 1 | 2
4 | 4 | 3 | -1 | 0 | 3
(4 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost FROM edge_table',
2, 5,
false
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
1 | 1 | 2 | 4 | 1 | 0
2 | 2 | 5 | -1 | 0 | 1
(2 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost FROM edge_table',
11, 3,
false
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
1 | 1 | 11 | 11 | 1 | 0
2 | 2 | 6 | 5 | 1 | 1
3 | 3 | 3 | -1 | 0 | 2
(3 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost FROM edge_table',
11, 5,
false
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
1 | 1 | 11 | 11 | 1 | 0
2 | 2 | 6 | 8 | 1 | 1
3 | 3 | 5 | -1 | 0 | 2
(3 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost FROM edge_table',
array[2,11], 5,
false
);
seq | path_seq | start_vid | node | edge | cost | agg_cost
-----+----------+---------+------+------+------+----------
1 | 1 | 2 | 2 | 4 | 1 | 0
2 | 2 | 2 | 5 | -1 | 0 | 1
3 | 1 | 11 | 11 | 11 | 1 | 0
4 | 2 | 11 | 6 | 8 | 1 | 1
5 | 3 | 11 | 5 | -1 | 0 | 2
(5 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost FROM edge_table',
2, array[3,5],
false
);
seq | path_seq | end_vid | node | edge | cost | agg_cost
-----+----------+-------+------+------+------+----------
1 | 1 | 3 | 2 | 4 | 1 | 0
2 | 2 | 3 | 5 | 8 | 1 | 1
3 | 3 | 3 | 6 | 5 | 1 | 2
4 | 4 | 3 | 3 | -1 | 0 | 3
5 | 1 | 5 | 2 | 4 | 1 | 0
6 | 2 | 5 | 5 | -1 | 0 | 1
(6 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost FROM edge_table',
array[2, 11], array[3,5],
false
);
seq | path_seq | start_vid | end_vid | node | edge | cost | agg_cost
-----+----------+---------+-------+------+------+------+----------
1 | 1 | 2 | 3 | 2 | 4 | 1 | 0
2 | 2 | 2 | 3 | 5 | 8 | 1 | 1
3 | 3 | 2 | 3 | 6 | 5 | 1 | 2
4 | 4 | 2 | 3 | 3 | -1 | 0 | 3
5 | 1 | 2 | 5 | 2 | 4 | 1 | 0
6 | 2 | 2 | 5 | 5 | -1 | 0 | 1
7 | 1 | 11 | 3 | 11 | 11 | 1 | 0
8 | 2 | 11 | 3 | 6 | 5 | 1 | 1
9 | 3 | 11 | 3 | 3 | -1 | 0 | 2
10 | 1 | 11 | 5 | 11 | 11 | 1 | 0
11 | 2 | 11 | 5 | 6 | 8 | 1 | 1
12 | 3 | 11 | 5 | 5 | -1 | 0 | 2
(12 rows)
Equvalences between signatures¶
-- V2
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
2, 3,
true, -- directed flag
true -- has_rcost
);
seq | id1 | id2 | cost
-----+-----+-----+------
0 | 2 | 4 | 1
1 | 5 | 8 | 1
2 | 6 | 9 | 1
3 | 9 | 16 | 1
4 | 4 | 3 | 1
5 | 3 | -1 | 0
(6 rows)
-- V3
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
2, 3,
true -- directed flag
);
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
2,3
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
1 | 1 | 2 | 4 | 1 | 0
2 | 2 | 5 | 8 | 1 | 1
3 | 3 | 6 | 9 | 1 | 2
4 | 4 | 9 | 16 | 1 | 3
5 | 5 | 4 | 3 | 1 | 4
6 | 6 | 3 | -1 | 0 | 5
(6 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
2, array[3],
true
);
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
2, array[3]
);
seq | path_seq | end_vid | node | edge | cost | agg_cost
-----+----------+-------+------+------+------+----------
1 | 1 | 3 | 2 | 4 | 1 | 0
2 | 2 | 3 | 5 | 8 | 1 | 1
3 | 3 | 3 | 6 | 9 | 1 | 2
4 | 4 | 3 | 9 | 16 | 1 | 3
5 | 5 | 3 | 4 | 3 | 1 | 4
6 | 6 | 3 | 3 | -1 | 0 | 5
(6 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
array[2], array[3],
true
);
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
array[2], array[3]
);
seq | path_seq | start_vid | end_vid | node | edge | cost | agg_cost
-----+----------+---------+-------+------+------+------+----------
1 | 1 | 2 | 3 | 2 | 4 | 1 | 0
2 | 2 | 2 | 3 | 5 | 8 | 1 | 1
3 | 3 | 2 | 3 | 6 | 9 | 1 | 2
4 | 4 | 2 | 3 | 9 | 16 | 1 | 3
5 | 5 | 2 | 3 | 4 | 3 | 1 | 4
6 | 6 | 2 | 3 | 3 | -1 | 0 | 5
(6 rows)
Equivalences between signatures¶
-- V2
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
2, 3,
false, -- directed flag
true -- has_rcost
);
seq | id1 | id2 | cost
-----+-----+-----+------
0 | 2 | 2 | 1
1 | 3 | -1 | 0
(2 rows)
-- V3
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
2, 3,
false -- directed flag
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
1 | 1 | 2 | 2 | 1 | 0
2 | 2 | 3 | -1 | 0 | 1
(2 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
2, array[3],
false
);
seq | path_seq | end_vid | node | edge | cost | agg_cost
-----+----------+-------+------+------+------+----------
1 | 1 | 3 | 2 | 2 | 1 | 0
2 | 2 | 3 | 3 | -1 | 0 | 1
(2 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
array[2], 3,
false
);
seq | path_seq | start_vid | node | edge | cost | agg_cost
-----+----------+---------+------+------+------+----------
1 | 1 | 2 | 2 | 2 | 1 | 0
2 | 2 | 2 | 3 | -1 | 0 | 1
(2 rows)
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
array[2], array[3],
false
);
seq | path_seq | start_vid | end_vid | node | edge | cost | agg_cost
-----+----------+---------+-------+------+------+------+----------
1 | 1 | 2 | 3 | 2 | 2 | 1 | 0
2 | 2 | 2 | 3 | 3 | -1 | 0 | 1
(2 rows)
The queries use the Sample Data network.
History
- Renamed in version 2.0.0
- Added functionality in version 2.1.0