pgr_bdAstar
— Returns the shortest path using A* algorithm.
Availability:
pgr_bdAstar(edges_sql, start_vid, end_vid)
pgr_bdAstar(edges_sql, start_vid, end_vid, directed [, heuristic, factor, epsilon])
RETURNS SET OF (seq, path_seq , node, edge, cost, agg_cost)
OR EMPTY SET
Warning
Experimental functions
pgr_bdAstar(edges_sql, start_vid, end_vids [, directed, heuristic, factor, epsilon])
pgr_bdAstar(edges_sql, start_vids, end_vid [, directed, heuristic, factor, epsilon])
pgr_bdAstar(edges_sql, start_vids, end_vids [, directed, heuristic, factor, epsilon])
RETURNS SET OF (seq, path_seq [, start_vid] [, end_vid], node, edge, cost, agg_cost)
OR EMPTY SET
Using these signatures, will load once the graph and perform several one to one pgr_bdAstar
start_vid
and/or end_vid
in the result is used to distinguish to which path it belongs.Avaliability
pgr_bdAstar(edges_sql, start_vid, end_vid)
RETURNS SET OF (seq, path_seq, node, edge, cost, agg_cost)
start_vid
to the end_vid
Example:  Using the defaults 

SELECT * FROM pgr_bdAstar(
'SELECT id, source, target, cost, reverse_cost, x1,y1,x2,y2
FROM edge_table',
2, 3
);
seq  path_seq  node  edge  cost  agg_cost
+++++
1  1  2  4  1  0
2  2  5  8  1  3
3  3  6  9  1  5
4  4  9  16  1  8
5  5  4  3  1  9
6  6  3  1  0  10
(6 rows)
pgr_bdAstar(edges_sql, start_vid, end_vid, directed [, heuristic, factor, epsilon])
RETURNS SET OF (seq, path_seq, node, edge, cost, agg_cost)
start_vid
to the end_vid
allowing the user to chooseNote
In the One to One signature, because of the deprecated signature existence, it is compulsory to indicate if the graph is directed or undirected.
Example:  Directed using Heuristic 2 

SELECT * FROM pgr_bdAstar(
'SELECT id, source, target, cost, reverse_cost, x1,y1,x2,y2
FROM edge_table',
2, 3,
true, heuristic := 2
);
seq  path_seq  node  edge  cost  agg_cost
+++++
1  1  2  4  1  0
2  2  5  8  1  2
3  3  6  9  1  3
4  4  9  16  1  4
5  5  4  3  1  5
6  6  3  1  0  6
(6 rows)
pgr_bdAstar(edges_sql, start_vid, end_vids [, directed, heuristic, factor, epsilon])
RETURNS SET OF (seq, path_seq, end_vid, node, edge, cost, agg_cost) or EMPTY SET
start_vid
to each end_vid
in end_vids
allowing the user to chooseExample:  Directed using Heuristic 3 and a factor of 3.5 

SELECT * FROM pgr_bdAstar(
'SELECT id, source, target, cost, reverse_cost, x1,y1,x2,y2
FROM edge_table',
2, ARRAY[3, 11],
heuristic := 3, factor := 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  25.5
3  3  3  6  9  1  38.75
4  4  3  9  16  1  64.25
5  5  3  4  3  1  65.25
6  6  3  3  1  0  66.25
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)
pgr_bdAstar(edges_sql, start_vids, end_vid [, directed, heuristic, factor, epsilon])
RETURNS SET OF (seq, path_seq, start_vid, node, edge, cost, agg_cost) or EMPTY SET
start_vid
in start_vids
to the end_vid
allowing the user to chooseExample:  Undirected graph with Heuristic 4 

SELECT * FROM pgr_bdAstar(
'SELECT id, source, target, cost, reverse_cost, x1,y1,x2,y2
FROM edge_table',
ARRAY[2, 7], 3,
false, heuristic := 4
);
seq  path_seq  start_vid  node  edge  cost  agg_cost
++++++
1  1  2  2  2  1  0
2  2  2  3  1  0  1
3  1  7  7  6  1  0
4  2  7  8  7  1  3.23606797749979
5  3  7  5  8  1  5.65028153987288
6  4  7  6  5  1  6.65028153987288
7  5  7  3  1  0  7.65028153987288
(7 rows)
pgr_bdAstar(edges_sql, start_vids, end_vids [, directed, heuristic, factor, epsilon])
RETURNS SET OF (seq, path_seq, start_vid, end_vid, node, edge, cost, agg_cost) or EMPTY SET
start_vid
in start_vids
to each end_vid
in end_vids
allowing the user to chooseExample:  Directed graph with a factor of 0.5 

SELECT * FROM pgr_bdAstar(
'SELECT id, source, target, cost, reverse_cost, x1,y1,x2,y2
FROM edge_table',
ARRAY[2, 7], ARRAY[3, 11],
factor := 0.5
);
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  2
3  3  2  3  6  9  1  3.5
4  4  2  3  9  16  1  4.5
5  5  2  3  4  3  1  5.5
6  6  2  3  3  1  0  6.5
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  2.5
13  3  7  3  5  8  1  4.5
14  4  7  3  6  9  1  6
15  5  7  3  9  16  1  7
16  6  7  3  4  3  1  8
17  7  7  3  3  1  0  9
18  1  7  11  7  6  1  0
19  2  7  11  8  7  1  1
20  3  7  11  5  8  1  2
21  4  7  11  6  11  1  3
22  5  7  11  11  1  0  4
(22 rows)
edges_sql:  an SQL query, which should return a set of rows with the following columns: 

Column  Type  Default  Description 

id  ANYINTEGER 
Identifier of the edge.  
source  ANYINTEGER 
Identifier of the first end point vertex of the edge.  
target  ANYINTEGER 
Identifier of the second end point vertex of the edge.  
cost  ANYNUMERICAL 
Weight of the edge (source, target)


reverse_cost  ANYNUMERICAL 
1  Weight of the edge (target, source),

x1  ANYNUMERICAL 
X coordinate of source vertex.  
y1  ANYNUMERICAL 
Y coordinate of source vertex.  
x2  ANYNUMERICAL 
X coordinate of target vertex.  
y2  ANYNUMERICAL 
Y coordinate of target vertex. 
Where:
ANYINTEGER:  SMALLINT, INTEGER, BIGINT 

ANYNUMERICAL:  SMALLINT, INTEGER, BIGINT, REAL, FLOAT 
Parameter  Type  Description 

edges_sql  TEXT 
Edges SQL query as described above. 
start_vid  ANYINTEGER 
Starting vertex identifier. 
start_vids  ARRAY[ANYINTEGER] 
Starting vertices identifierers. 
end_vid  ANYINTEGER 
Ending vertex identifier. 
end_vids  ARRAY[ANYINTEGER] 
Ending vertices identifiers. 
directed  BOOLEAN 

heuristic  INTEGER 
(optional). Heuristic number. Current valid values 0~5. Default

factor  FLOAT 
(optional). For units manipulation. \(factor > 0\). Default 1 . see Factor 
epsilon  FLOAT 
(optional). For less restricted results. \(epsilon >= 1\). Default 1 . 
Returns set of (seq, path_seq [, start_vid] [, end_vid], node, edge, cost, agg_cost)
Column  Type  Description 

seq  INT 
Sequential value starting from 1. 
path_id  INT 
Path identifier. Has value 1 for the first of a path. Used when there are multiple paths for the same start_vid to end_vid combination. 
path_seq  INT 
Relative position in the path. Has value 1 for the beginning of a path. 
start_vid  BIGINT 
Identifier of the starting vertex. Used when multiple starting vetrices are in the query. 
end_vid  BIGINT 
Identifier of the ending vertex. Used when multiple ending vertices are in the query. 
node  BIGINT 
Identifier of the node in the path from start_vid to end_vid . 
edge  BIGINT 
Identifier 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 
Aggregate cost from start_v to node . 
Indices and tables