pgr_dijkstra - pgRouting Manual (2.5)
pgr_dijkstra
pgr_dijkstra - Returns the shortest path(s) using Dijkstra algorithm. In particular, the Dijkstra algorithm implemented by Boost.Graph.
Boost Graph Inside
Availability
- pgr_dijkstra(one to one) 2.0.0, signature change 2.1.0
- pgr_dijkstra(other signatures) 2.1.0
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.
Characteristics
- 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 \(\infty\)
-
When the starting vertex and ending vertex are the same, there is no path.
- For optimization purposes, any duplicated value in the start_vids or end_vids are ignored.
-
The returned values are ordered:
- start_vid ascending
- end_vid ascending
- Running time: \(O( start\_vids * (V \log V + E))\)
Signature Summary
pgr_dijkstra(edges_sql, start_vid, end_vid)
pgr_dijkstra(edges_sql, start_vid, end_vid, directed:=true)
pgr_dijkstra(edges_sql, start_vid, end_vids, directed:=true)
pgr_dijkstra(edges_sql, start_vids, end_vid, directed:=true)
pgr_dijkstra(edges_sql, start_vids, end_vids, directed:=true)
RETURNS SET OF (seq, path_seq [, start_vid] [, end_vid], node, edge, cost, agg_cost)
OR EMPTY SET
Signatures
Minimal signature
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
The minimal signature is for a directed graph from one start_vid to one end_vid .
| Example: |
|---|
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)
pgr_dijkstra One to One
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
- This signature finds the shortest path from one start_vid to one end_vid :
-
- on a directed graph when directed flag is missing or is set to true .
- on an undirected graph when directed flag is set to false .
| Example: |
|---|
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)
pgr_dijkstra One 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 finds the shortest path from one start_vid to each end_vid in end_vids :
-
- on a directed graph when directed flag is missing or is set to true .
- on an undirected graph when directed flag is set to false .
Using this signature, will load once the graph and perform a one to one pgr_dijkstra where the starting vertex is fixed, and stop when all end_vids are reached.
- The result is equivalent to the union of the results of the one to one pgr_dijkstra .
- The extra end_vid in the result is used to distinguish to which path it belongs.
| Example: |
|---|
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)
pgr_dijkstra Many to One
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 finds the shortest path from each start_vid in start_vids to one end_vid :
-
- on a directed graph when directed flag is missing or is set to true .
- on an undirected graph when directed flag is set to false .
Using this signature, will load once the graph and perform several one to one pgr_dijkstra where the ending vertex is fixed.
- The result is the union of the results of the one to one pgr_dijkstra .
- The extra start_vid in the result is used to distinguish to which path it belongs.
| Example: |
|---|
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)
pgr_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 finds the shortest path from each start_vid in start_vids to each end_vid in end_vids :
-
- on a directed graph when directed flag is missing or is set to true .
- on an undirected graph when directed flag is set to false .
Using this signature, will load once the graph and perform several one to Many pgr_dijkstra for all start_vids .
- The result is the union of the results of the one to one pgr_dijkstra .
- The extra start_vid in the result is used to distinguish to which path it belongs.
The extra start_vid and end_vid in the result is used to distinguish to which path it belongs.
| Example: |
|---|
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)
Description of the Signatures
Description of the edges_sql query for dijkstra like functions
| edges_sql: | an SQL query, which should return a set of rows with the following columns: |
|---|
| 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 |
Description of the parameters of the signatures
| Column | Type | Default | Description |
|---|---|---|---|
| sql | TEXT | SQL query as described above. | |
| 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 |
|
Description of the return values for a path
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 . |
Additional 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 Network for queries marked as directed and cost and reverse_cost columns are used
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)
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)
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 Network for queries marked as undirected and cost and reverse_cost columns are used
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 12 1 0
4 2 11 10 10 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 Network for queries marked as directed and only cost column is used
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 Network for queries marked as undirected and only cost column is used
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 12 1 0
4 2 11 10 10 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
| Examples: | For queries marked as directed with cost and reverse_cost columns |
|---|
The examples in this section use the following:
SELECT * FROM pgr_dijkstra(
'SELECT id, source, target, cost, reverse_cost FROM edge_table',
2, 3,
TRUE
);
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',
2,3
);
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
);
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',
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
);
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)
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)
| Examples: | For queries marked as undirected with cost and reverse_cost columns |
|---|
The examples in this section use the following:
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, 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)
See Also
- http://en.wikipedia.org/wiki/Dijkstra%27s_algorithm
- The queries use the Sample Data network.
Indices and tables