pgr_articulationPoints
- Return the articulation points of an undirected graph.
Availability
seq
is removedSupport
Those vertices that belong to more than one biconnected component are called articulation points or, equivalently, cut vertices. Articulation points are vertices whose removal would increase the number of connected components in the graph. This implementation can only be used with an undirected graph.
The main characteristics are:
pgr_articulationPoints(Edges SQL)
RETURNS SET OF (node)
OR EMPTY SET
Example: | The articulation points of the graph |
---|
SELECT * FROM pgr_articulationPoints(
'SELECT id, source, target, cost, reverse_cost FROM edge_table'
);
node
------
2
5
8
10
(4 rows)
Parameter | Type | Default | Description |
---|---|---|---|
Edges SQL | TEXT |
Inner query as described below. |
edges SQL: | an SQL query of an undirected graph, 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 |
Indices and tables