pgr_edwardMoore
— Returns the shortest path(s) using Edward-Moore algorithm.
Edward Moore’s Algorithm is an improvement of the Bellman-Ford Algorithm.
Warning
Possible server crash
Warning
Experimental functions
Availability
Edward Moore’s Algorithm is an improvement of the Bellman-Ford Algorithm. It can compute the shortest paths from a single source vertex to all other vertices in a weighted directed graph. The main difference between Edward Moore’s Algorithm and Bellman Ford’s Algorithm lies in the run time.
The worst-case running time of the algorithm is \(O(| V | * | E |)\) similar to the time complexity of Bellman-Ford algorithm. However, experiments suggest that this algorithm has an average running time complexity of \(O( | E | )\) for random graphs. This is significantly faster in terms of computation speed.
Thus, the algorithm is at-best, significantly faster than Bellman-Ford algorithm and is at-worst, as good as Bellman-Ford algorithm
pgr_edwardMoore(edges_sql, start_vid, end_vid [, directed])
pgr_edwardMoore(edges_sql, start_vid, end_vids [, directed])
pgr_edwardMoore(edges_sql, start_vids, end_vid [, directed])
pgr_edwardMoore(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
pgr_edwardMoore(TEXT edges_sql, BIGINT start_vid, BIGINT end_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_edwardMoore(
'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)
pgr_edwardMoore(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
Example: | From vertex \(2\) to vertex \(3\) on an undirected graph |
---|
SELECT * FROM pgr_edwardMoore(
'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)
pgr_edwardMoore(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
Example: | From vertex \(2\) to vertices \(\{3, 5\}\) on an undirected graph |
---|
SELECT * FROM pgr_edwardMoore(
'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)
pgr_edwardMoore(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
Example: | From vertices \(\{2, 11\}\) to vertex \(5\) on a directed graph |
---|
SELECT * FROM pgr_edwardMoore(
'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)
pgr_edwardMoore(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
Example: | From vertices \(\{2, 11\}\) to vertices \(\{3, 5\}\) on an undirected graph |
---|
SELECT * FROM pgr_edwardMoore(
'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)
Parameter | Type | Default | Description |
---|---|---|---|
edges_sql | TEXT |
Inner SQL query as described below. | |
start_vid | BIGINT |
Identifier of the starting vertex of the path. | |
start_vids | ARRAY[BIGINT] |
Array of identifiers of starting vertices. | |
end_vid | BIGINT |
Identifier of the ending vertex of the path. | |
end_vids | ARRAY[BIGINT] |
Array of identifiers of ending vertices. | |
directed | BOOLEAN |
true |
|
Column | Type | Default | Description |
---|---|---|---|
id | ANY-INTEGER |
Identifier of the edge. | |
source | ANY-INTEGER |
Identifier of the first end point vertex of the edge. | |
target | ANY-INTEGER |
Identifier of the second end point vertex of the edge. | |
cost | ANY-NUMERICAL |
Weight of the edge (source, target)
|
|
reverse_cost | ANY-NUMERICAL |
-1 | Weight of the edge (target, source),
|
Where:
ANY-INTEGER: | SMALLINT, INTEGER, BIGINT |
---|---|
ANY-NUMERICAL: | SMALLINT, INTEGER, BIGINT, REAL, FLOAT |
Returns set of (seq, path_id, 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. Returned when multiple starting vetrices are in the query. |
end_vid | BIGINT |
Identifier of the ending vertex. Returned 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 . |
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 Network for queries marked as directed and cost and reverse_cost columns are used
SELECT * FROM pgr_edwardMoore(
'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_edwardMoore(
'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)
SELECT * FROM pgr_edwardMoore(
'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_edwardMoore(
'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_edwardMoore(
'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)
SELECT * FROM pgr_edwardMoore(
'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_edwardMoore(
'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 Network for queries marked as undirected and cost and reverse_cost columns are used
SELECT * FROM pgr_edwardMoore(
'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_edwardMoore(
'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_edwardMoore(
'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_edwardMoore(
'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_edwardMoore(
'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_edwardMoore(
'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_edwardMoore(
'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 Network for queries marked as directed and only cost column is used
SELECT * FROM pgr_edwardMoore(
'SELECT id, source, target, cost FROM edge_table',
2, 3
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
(0 rows)
SELECT * FROM pgr_edwardMoore(
'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_edwardMoore(
'SELECT id, source, target, cost FROM edge_table',
11, 3
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
(0 rows)
SELECT * FROM pgr_edwardMoore(
'SELECT id, source, target, cost FROM edge_table',
11, 5
);
seq | path_seq | node | edge | cost | agg_cost
-----+----------+------+------+------+----------
(0 rows)
SELECT * FROM pgr_edwardMoore(
'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_edwardMoore(
'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_edwardMoore(
'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 Network for queries marked as undirected and only cost column is used
SELECT * FROM pgr_edwardMoore(
'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_edwardMoore(
'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_edwardMoore(
'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_edwardMoore(
'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_edwardMoore(
'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_edwardMoore(
'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_edwardMoore(
'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)
Indices and tables