DFS - Category¶
Traversal using Depth First Search.
Proposed
Warning
Proposed functions for next mayor release.
They are not officially in the current release.
They will likely officially be part of the next mayor release:
The functions make use of ANY-INTEGER and ANY-NUMERICAL
Name might not change. (But still can)
Signature might not change. (But still can)
Functionality might not change. (But still can)
pgTap tests have being done. But might need more.
Documentation might need refinement.
pgr_depthFirstSearch - Proposed - Depth first search traversal of the graph.
It’s implementation is only on undirected graph.
Process is done only on edges with positive costs.
When the graph is connected
The resulting edges make up a tree
When the graph is not connected,
Finds a minimum spanning tree for each connected component.
The resulting edges make up a forest.
Parameters¶
Parameter |
Type |
Description |
---|---|---|
|
Edges SQL as described below. |
|
Root vid |
|
Identifier of the root vertex of the tree.
|
Root vids |
|
Array of identifiers of the root vertices.
|
Where:
- ANY-INTEGER
SMALLINT, INTEGER, BIGINT
- ANY-NUMERIC
SMALLINT, INTEGER, BIGINT, REAL, FLOAT, NUMERIC
DFS optional parameters¶
Parameter |
Type |
Default |
Description |
---|---|---|---|
|
|
\(9223372036854775807\) |
Upper limit of the depth of the tree.
|
Inner queries¶
Edges SQL¶
Column |
Type |
Default |
Description |
---|---|---|---|
|
ANY-INTEGER |
Identifier of the edge. |
|
|
ANY-INTEGER |
Identifier of the first end point vertex of the edge. |
|
|
ANY-INTEGER |
Identifier of the second end point vertex of the edge. |
|
|
ANY-NUMERICAL |
Weight of the edge ( |
|
|
ANY-NUMERICAL |
-1 |
Weight of the edge (
|
Where:
- ANY-INTEGER
SMALLINT
,INTEGER
,BIGINT
- ANY-NUMERICAL
SMALLINT
,INTEGER
,BIGINT
,REAL
,FLOAT
Result Columns¶
Returns SET OF (seq, depth, start_vid, node, edge, cost, agg_cost)
Parameter |
Type |
Description |
---|---|---|
|
|
Sequential value starting from \(1\). |
|
|
Depth of the
|
|
|
Identifier of the root vertex. |
|
|
Identifier of |
|
|
Identifier of the
|
|
|
Cost to traverse |
|
|
Aggregate cost from |
Where:
- ANY-INTEGER
SMALLINT, INTEGER, BIGINT
- ANY-NUMERIC
SMALLINT, INTEGER, BIGINT, REAL, FLOAT, NUMERIC
See Also¶
Indices and tables