pgr_bdDijkstra - pgRouting Manual (3.2)
pgr_bdDijkstra
pgr_bdDijkstra
- Returns the shortest path(s) using Bidirectional Dijkstra algorithm.
Availability:
-
Version 3.2.0
-
New proposed function:
-
pgr_bdDijkstra(Combinations)
-
-
-
Version 3.0.0
-
Official function
-
-
Version 2.5.0
-
New Proposed functions:
-
pgr_bdDijkstra(One to Many)
-
pgr_bdDijkstra(Many to One)
-
pgr_bdDijkstra(Many to Many)
-
-
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Version 2.4.0
-
Signature change on pgr_bdDijsktra(One to One)
-
Old signature no longer supported
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-
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Version 2.0.0
-
Official pgr_bdDijkstra(One to One)
-
Description
The main characteristics are:
-
Process is done only on edges with positive costs.
-
Values are returned when there is a path.
-
When the starting vertex and ending vertex are the same, there is no path.
-
The agg_cost the non included values (v, v) is 0
-
-
When the starting vertex and ending vertex are the different and there is no path:
-
The agg_cost the non included values (u, v) is \(\infty\)
-
-
Running time (worse case scenario): \(O((V \log V + E))\)
-
For large graphs where there is a path bewtween the starting vertex and ending vertex:
-
It is expected to terminate faster than pgr_dijkstra
-
Signatures
Summary
pgr_bdDijkstra(Edges SQL, start_vid, end_vid [, directed])
pgr_bdDijkstra(Edges SQL, start_vid, end_vids [, directed])
pgr_bdDijkstra(Edges SQL, start_vids, end_vid [, directed])
pgr_bdDijkstra(Edges SQL, start_vids, end_vids [, directed])
pgr_bdDijkstra(Edges SQL, Combinations SQL [, directed]) -- Proposed on v3.2
RETURNS SET OF (seq, path_seq [, start_vid] [, end_vid], node, edge, cost, agg_cost)
OR EMPTY SET
Using defaults
pgr_bdDijkstra(Edges SQL, start_vid, end_vid)
RETURNS SET OF (seq, path_seq, node, edge, cost, agg_cost)
OR EMPTY SET
- Example :
-
From vertex \(2\) to vertex \(3\)
SELECT * FROM pgr_bdDijkstra(
'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)
One to One
pgr_bdDijkstra(Edges SQL, start_vid, end_vid [, directed])
RETURNS SET OF (seq, path_seq, node, edge, cost, agg_cost)
OR EMPTY SET
- Example :
-
From vertex \(2\) to vertex \(3\) on an undirected graph
SELECT * FROM pgr_bdDijkstra(
'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)
One to many
pgr_bdDijkstra(Edges SQL, start_vid, end_vids [, directed])
RETURNS SET OF (seq, path_seq, end_vid, node, edge, cost, agg_cost)
OR EMPTY SET
- Example :
-
From vertex \(2\) to vertices \(\{3, 11\}\) on a directed graph
SELECT * FROM pgr_bdDijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
2, ARRAY[3, 11]);
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 11 2 4 1 0
8 2 11 5 8 1 1
9 3 11 6 11 1 2
10 4 11 11 -1 0 3
(10 rows)
Many to One
pgr_bdDijkstra(Edges SQL, start_vids, end_vid [, directed])
RETURNS SET OF (seq, path_seq, start_vid, node, edge, cost, agg_cost)
OR EMPTY SET
- Example :
-
From vertices \(\{2, 7\}\) to vertex \(3\) on a directed graph
SELECT * FROM pgr_bdDijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
ARRAY[2, 7], 3);
seq path_seq start_vid node edge cost agg_cost
-----+----------+-----------+------+------+------+----------
1 1 2 2 4 1 0
2 2 2 5 8 1 1
3 3 2 6 9 1 2
4 4 2 9 16 1 3
5 5 2 4 3 1 4
6 6 2 3 -1 0 5
7 1 7 7 6 1 0
8 2 7 8 7 1 1
9 3 7 5 8 1 2
10 4 7 6 9 1 3
11 5 7 9 16 1 4
12 6 7 4 3 1 5
13 7 7 3 -1 0 6
(13 rows)
Many to Many
pgr_bdDijkstra(Edges SQL, start_vids, end_vids [, directed])
RETURNS SET OF (seq, path_seq, start_vid, end_vid, node, edge, cost, agg_cost)
OR EMPTY SET
- Example :
-
From vertices \(\{2, 7\}\) to vertices \(\{3, 11\}\) on a directed graph
SELECT * FROM pgr_bdDijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
ARRAY[2, 7], ARRAY[3, 11]);
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 11 2 4 1 0
8 2 2 11 5 8 1 1
9 3 2 11 6 11 1 2
10 4 2 11 11 -1 0 3
11 1 7 3 7 6 1 0
12 2 7 3 8 7 1 1
13 3 7 3 5 8 1 2
14 4 7 3 6 9 1 3
15 5 7 3 9 16 1 4
16 6 7 3 4 3 1 5
17 7 7 3 3 -1 0 6
18 1 7 11 7 6 1 0
19 2 7 11 8 7 1 1
20 3 7 11 5 10 1 2
21 4 7 11 10 12 1 3
22 5 7 11 11 -1 0 4
(22 rows)
Combinations
pgr_bdDijkstra(Edges SQL, Combinations SQL [, directed])
RETURNS SET OF (seq, path_seq, start_vid, end_vid, node, edge, cost, agg_cost)
OR EMPTY SET
- Example :
-
Using a combinations table on a directed graph.
SELECT * FROM pgr_bdDijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
'SELECT * FROM ( VALUES (2, 3), (7, 11) ) AS t(source, target)');
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 7 11 7 6 1 0
8 2 7 11 8 7 1 1
9 3 7 11 5 10 1 2
10 4 7 11 10 12 1 3
11 5 7 11 11 -1 0 4
(11 rows)
Parameters
|
Parameter |
Type |
Default |
Description |
|---|---|---|---|
|
Edges SQL |
|
Edges query as described below |
|
|
Combinations SQL |
|
Combinations query as described below |
|
|
start_vid |
|
Identifier of the starting vertex of the path. |
|
|
start_vids |
|
Array of identifiers of starting vertices. |
|
|
end_vid |
|
Identifier of the ending vertex of the path. |
|
|
end_vids |
|
Array of identifiers of ending vertices. |
|
|
directed |
|
|
|
Inner queries
Edges query
|
Column |
Type |
Default |
Description |
|---|---|---|---|
|
id |
|
Identifier of the edge. |
|
|
source |
|
Identifier of the first end point vertex of the edge. |
|
|
target |
|
Identifier of the second end point vertex of the edge. |
|
|
cost |
|
Weight of the edge (source, target)
|
|
|
reverse_cost |
|
-1 |
Weight of the edge (target, source) ,
|
Where:
- ANY-INTEGER :
-
SMALLINT, INTEGER, BIGINT
- ANY-NUMERICAL :
-
SMALLINT, INTEGER, BIGINT, REAL, FLOAT
Combinations query
|
Column |
Type |
Default |
Description |
|---|---|---|---|
|
source |
|
Identifier of the first end point vertex of the edge. |
|
|
target |
|
Identifier of the second end point vertex of the edge. |
Where:
- ANY-INTEGER :
-
SMALLINT, INTEGER, BIGINT
Result Columns
Returns set of
(seq,
path_id,
path_seq
[,
start_vid]
[,
end_vid],
node,
edge,
cost,
agg_cost)
|
Column |
Type |
Description |
|---|---|---|
|
seq |
|
Sequential value starting from 1 . |
|
path_id |
|
Path identifier. Has value
1
for the first of a path. Used when there are multiple paths for the same
|
|
path_seq |
|
Relative position in the path. Has value 1 for the beginning of a path. |
|
start_vid |
|
Identifier of the starting vertex. Returned when multiple starting vetrices are in the query. |
|
end_vid |
|
Identifier of the ending vertex. Returned when multiple ending vertices are in the query. |
|
node |
|
Identifier of the node in the path from
|
|
edge |
|
Identifier of the edge used to go from
|
|
cost |
|
Cost to traverse from
|
|
agg_cost |
|
Aggregate cost from
|
See Also
-
The queries use the Sample Data network.
Indices and tables