# tf\_graph\_shortest\_path Given a distance-weighted directed graph, consisting of a query`CURSOR` input consisting of the starting and ending node for each edge and a distance, and a specified origin and destination node, `tf_graph_shortest_path` computes the shortest distance-weighted path through the graph between `origin_node` and `destination_node`, returning a row for each node along the computed shortest path, with the traversal-ordered index of that node and the cumulative distance from the `origin_node` to that node. If either `origin_node` or `destination_node` do not exist, an error is returned. ``` SELECT * FROM TABLE( tf_graph_shortest_path( edge_list => CURSOR( SELECT node1, node2, distance FROM table ), origin_node => , destination_node => ) ``` **Input Arguments** | Parameter | Description | Data Types | | ------------------ | ------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------ | | `node1` | Origin node column in directed edge list CURSOR | Column< INT \| BIGINT \| TEXT ENCODED DICT> | | `node2` | Destination node column in directed edge list CURSOR | Column< INT \| BIGINT \| TEXT ENCODED DICT> (must be the same type as `node1`) | | `distance` | Distance between origin and destination node in directed edge list CURSOR | Column< INT \| BIGINT \| FLOAT \| DOUBLE > | | `origin_node` | The origin node to start graph traversal from. If not a value present in `edge_list.node1`, will cause empty result set to be returned. | BIGINT \| TEXT ENCODED DICT | | `destination_node` | The destination node to finish graph traversal at. If not a value present in `edge_list.node1`, will cause empty result set to be returned. | BIGINT \| TEXT ENCODED DICT | **Output Columns**
NameDescriptionData Types
path_stepThe index of this node along the path traversal from origin_node to destination_node, with the first node (the origin_node) indexed as 1.Column< INT >
nodeThe current node along the path traversal from origin_node to destination_node. The first node (as denoted by path_step = 1) will always be the input origin_node, and the final node (as denoted by MAX(path_step)) will always be the input destination_node.Column < INT | BIGINT | TEXT ENCODED DICT> (same type as the node1 and node2 input columns)
cume_distanceThe cumulative distance adding all input distance values from the origin_node to the current node.Column < INT | BIGINT | FLOAT | DOUBLE> (same type as the distance input column)
**Example A** ``` /* Compute the shortest flight route on United Airlines for the year 2008 as measured by flight time between origin airport 'RDU' (Raleigh-Durham, NC) and destination airport 'SAT' (San Antonio, TX), adding 60 minutes for each leg to account for boarding/plane change time costs, and only counting routes that were flown at least 300 times during the year. */ SELECT * FROM TABLE( tf_graph_shortest_path( edge_list => CURSOR( SELECT origin, dest, /* Add 60 minutes to each leg to account for boarding/plane change costs */ AVG(airtime) + 60 as avg_airtime FROM flights_2008 WHERE carrier_name = 'United Air Lines' GROUP by origin, dest HAVING COUNT(*) > 300 ), origin_node => 'RDU', destination_node => 'SAT' ) ) ORDER BY path_step path_step|node|cume_distance 1|RDU|0 2|ORD|167 3|DEN|354 4|SAT|519 ``` **Example B** ``` /* Compute the shortest path between along a time-traversal weighted edge graph of roads in the Eastern United States between a location in North Carolina and a location in Maine, joining to a node locations table to output the lon/lat pairs of each node. */ select path_step, node, lon, lat, cume_distance from table( tf_graph_shortest_path( cursor( select node1, node2, traversal_time from usa_roads_east_time ), 1561955, 1591319 ) ), USA_roads_east_coords where node = node_id order by cume_distance desc limit 20; path_step|node|lon|lat|cume_distance 4380|1591319|-71.55136299999999|43.75256|13442017 4379|1591989|-71.55174099999999|43.75245|13441199 4378|1589348|-71.554147|43.752464|13436371 4377|2315795|-71.554867|43.752489|13434924 4376|1589286|-71.55497099999999|43.752113|13434214 4375|1589285|-71.555049|43.751833|13433685 4374|2315785|-71.555999|43.750704|13431238 4373|2315973|-71.55798799999999|43.748622|13426553 4372|2315950|-71.56366299999999|43.746268|13417798 4371|1589788|-71.56476599999999|43.745765|13416053 4370|1591997|-71.56484|43.745691|13415884 4369|1589787|-71.564886|43.745645|13415779 4368|2315951|-71.56517599999999|43.745353|13415113 4367|2315952|-71.56659499999999|43.744599|13412756 4366|1591999|-71.56685899999999|43.744565|13412397 4365|543394|-71.567357|43.744335|13411606 4364|543393|-71.567832|43.744116|13410852 4363|543392|-71.571827|43.743673|13405444 4362|541181|-71.57268499999999|43.743802|13404271 4361|1589786|-71.572964|43.743844|13403890 ```

The computed shortest path along a time-traversal weighted road edge graph for the eastern US.

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