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  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),

Where:
ANYINTEGER:  SMALLINT, INTEGER, BIGINT 

ANYNUMERICAL:  SMALLINT, INTEGER, BIGINT, REAL, FLOAT 
Indices and tables