# Components - Family of functions¶

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

• Supported versions: current(3.1) 3.0 2.6

• Unsupported versions: 2.5

## 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)

• When negative: edge (source, target) does not exist, therefore it’s not part of the graph.

reverse_cost

ANY-NUMERICAL

-1

Weight of the edge (target, source),

• When negative: edge (target, source) does not exist, therefore it’s not part of the graph.

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.