pgr_bdDijkstraCost¶
pgr_bdDijkstraCost
— Returns the shortest path(s)’s cost using Bidirectional Dijkstra algorithm.
Availability:
Version 3.0.0
Official function
Version 2.5.0
New proposed function
Support
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_bdDijkstraCost(edges_sql, from_vid, to_vid [, directed])
pgr_bdDijkstraCost(edges_sql, from_vid, to_vids [, directed])
pgr_bdDijkstraCost(edges_sql, from_vids, to_vid [, directed])
pgr_bdDijkstraCost(edges_sql, from_vids, to_vids [, directed])
RETURNS SET OF (start_vid, end_vid, agg_cost)
OR EMPTY SET
Using default
pgr_bdDijkstraCost(edges_sql, from_vid, to_vid)
RETURNS SET OF (seq, path_seq, node, edge, cost, agg_cost)
OR EMPTY SET
 Example
From vertex \(2\) to vertex \(3\) on a directed graph
SELECT * FROM pgr_bdDijkstraCost(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
2, 3
);
start_vid  end_vid  agg_cost
++
2  3  5
(1 row)
One to One¶
pgr_bdDijkstraCost(edges_sql, from_vid, to_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_bdDijkstraCost(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
2, 3,
false
);
start_vid  end_vid  agg_cost
++
2  3  1
(1 row)
One to Many¶
pgr_bdDijkstraCost(edges_sql, from_vid, to_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_bdDijkstraCost(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
2, ARRAY[3, 11]);
start_vid  end_vid  agg_cost
++
2  3  5
2  11  3
(2 rows)
Many to One¶
pgr_bdDijkstraCost(edges_sql, from_vids, to_vids [, 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_bdDijkstraCost(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
ARRAY[2, 7], 3);
start_vid  end_vid  agg_cost
++
2  3  5
7  3  6
(2 rows)
Many to Many¶
pgr_bdDijkstraCost(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_bdDijkstraCost(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
ARRAY[2, 7], ARRAY[3, 11]);
start_vid  end_vid  agg_cost
++
2  3  5
2  11  3
7  3  6
7  11  4
(4 rows)
Parameters¶
Parameter 
Type 
Default 
Description 

edges_sql 

Inner SQL 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 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:
 ANYINTEGER
SMALLINT, INTEGER, BIGINT
 ANYNUMERICAL
SMALLINT, INTEGER, BIGINT, REAL, FLOAT
Result Columns¶
Returns SET OF (start_vid, end_vid, agg_cost)
Column 
Type 
Description 

start_vid 

Identifier of the starting vertex. Used when multiple starting vetrices are in the query. 
end_vid 

Identifier of the ending vertex. Used when multiple ending vertices are in the query. 
agg_cost 

Aggregate cost from 