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 ANY-INTEGER and ANY-NUMERICAL
- 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 | TEXT |
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 | 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 |
Result Columns¶
pgr_connectedComponents & pgr_strongComponents¶
Returns set of (seq, component, node)
Column | Type | Description |
---|---|---|
seq | BIGINT |
Sequential value starting from 1. |
component | BIGINT |
Component identifier. It is equal to the minimum node identifier in the component. |
node | BIGINT |
Identifier of the vertex that belongs to component. |
pgr_biconnectedComponents¶
Returns set of (seq, component, edge)
Column | Type | Description |
---|---|---|
seq | BIGINT |
Sequential value starting from 1. |
component | BIGINT |
Component identifier. It is equal to the minimum edge identifier in the component. |
edge | BIGINT |
Identifier of the edge. |
pgr_articulationPoints¶
Returns set of (node)
Column | Type | Description |
---|---|---|
node | BIGINT |
Identifier of the vertex. |
pgr_bridges¶
Returns set of (edge)
Column | Type | Description |
---|---|---|
edge | BIGINT |
Identifier of the edge that is a bridge. |
pgr_makeConnected - Experimental¶
Returns set of (seq, start_vid, end_vid)
Column | Type | Description |
---|---|---|
seq | INT |
Sequential value starting from 1. |
start_vid | BIGINT |
Identifier of the first end point vertex of the edge. |
end_vid | BIGINT |
Identifier of the second end point vertex of the edge. |