OPG_APIS.FIND

Format

OPG_APIS.FIND_SP(
     edge_tab_name  IN VARCHAR2,
     source         IN NUMBER,
     dest           IN NUMBER,
     exp_tab        IN OUT VARCHAR2,
     dop            IN INTEGER,
     stats_freq     IN INTEGER DEFAULT 20000,
     path_output    OUT VARCHAR2,
     weights_output OUT VARCHAR2,
     edge_tab_name  IN VARCHAR2,
     options        IN VARCHAR2 DEFAULT NULL,
     scn            IN NUMBER DEFAULT NULL);

Description

Finds the shortest path between given source vertex and destination vertex in the property graph. It assumes each edge has a numeric weight property. (The actual edge property name is not significant.)

Parameters

edge_tab_name

Name of the property graph edge table.

source

Source (start) vertex ID.

dest

Destination (end) vertex ID.

exp_tab

Name of the expansion table to be used for shortest path calculations.

dop

Degree of parallelism for the operation.

stats_freq

Frequency for collecting statistics on the table.

path_output

The output shortest path. It consists of IDs of vertices on the shortest path, which are separated by the space character.

weights_output

The output shortest path weights. It consists of weights of edges on the shortest path, which are separated by the space character.

options

Additional settings for the operation. An optional string with one or more (comma-separated) of the following values:

CREATE_UNDIRECTED=T
REUSE_UNDIRECTED_TAB=T

scn

SCN for the edge table. It can be null.

Usage Notes

The property graph edge table must exist in the database, and the OPG_APIS.FIND_SP_PREP procedure must have already been called.

Examples

The following example prepares for shortest-path calculation, and then finds the shortest path from vertex 1 to vertex 35 in a property graph named mypg.

set serveroutput on
DECLARE
    w     varchar2(2000);
    wtExp varchar2(2000);
    vPath varchar2(2000);
BEGIN
    opg_apis.find_sp_prep('mypgGE$', wtExp, null);
    opg_apis.find_sp('mypgGE$', 1, 35,  wtExp, 1, 200000,  vPath, w, null, null);
    dbms_output.put_line('Shortest path ' || vPath);
    dbms_output.put_line('Path weights '  || w);
END;
/

The output will be similar to the following. It shows one shortest path starting from vertex 1, to vertex 2, and finally to the destination vertex (35).

Shortest path 1    2 35
Path weights 3 2   1 1