Components  Family of functions¶
pgr_connectedComponents  Connected components of an undirected graph.
pgr_strongComponents  Strongly connected components of a directed graph.
pgr_biconnectedComponents  Biconnected components of an undirected graph.
pgr_articulationPoints  Articulation points of an undirected graph.
pgr_bridges  Bridges of an undirected graph.
Experimental
Warning
Possible server crash
These functions might create a server crash
Warning
Experimental functions
They are not officially of the current release.
They likely will not be officially be part of the next release:
The functions might not make use of ANYINTEGER and ANYNUMERICAL
Name might change.
Signature might change.
Functionality might change.
pgTap tests might be missing.
Might need c/c++ coding.
May lack documentation.
Documentation if any might need to be rewritten.
Documentation examples might need to be automatically generated.
Might need a lot of feedback from the comunity.
Might depend on a proposed function of pgRouting
Might depend on a deprecated function of pgRouting
pgr_makeConnected  Experimental  Details of edges to make graph connected.
Parameters¶
Parameter 
Type 
Default 
Description 

Edges SQL 

Inner query as described below. 
Inner query¶
 Edges SQL
an SQL query which should return a set of rows with the following columns:
Column 
Type 
Default 
Description 

id 

Identifier of the edge. 

source 

Identifier of the first end point vertex of the edge. 

target 

Identifier of the second end point vertex of the edge. 

cost 

Weight of the edge (source, target)


reverse_cost 

1 
Weight of the edge (target, source),

Where:
 ANYINTEGER
SMALLINT, INTEGER, BIGINT
 ANYNUMERICAL
SMALLINT, INTEGER, BIGINT, REAL, FLOAT
Result Columns¶
pgr_connectedComponents & pgr_strongComponents¶
Returns set of (seq, component, node)
Column 
Type 
Description 

seq 

Sequential value starting from 1. 
component 

Component identifier. It is equal to the minimum node identifier in the component. 
node 

Identifier of the vertex that belongs to component. 
pgr_biconnectedComponents¶
Returns set of (seq, component, edge)
Column 
Type 
Description 

seq 

Sequential value starting from 1. 
component 

Component identifier. It is equal to the minimum edge identifier in the component. 
edge 

Identifier of the edge. 
pgr_articulationPoints¶
Returns set of (node)
Column 
Type 
Description 

node 

Identifier of the vertex. 
pgr_bridges¶
Returns set of (edge)
Column 
Type 
Description 

edge 

Identifier of the edge that is a bridge. 
pgr_makeConnected  Experimental¶
Returns set of (seq, start_vid, end_vid)
Column 
Type 
Description 

seq 

Sequential value starting from 1. 
start_vid 

Identifier of the first end point vertex of the edge. 
end_vid 

Identifier of the second end point vertex of the edge. 