OPG_APIS.FIND_CC_MAPPING

Format

OPG_APIS.FIND_CC_MAPPING_BASED(
     edge_tab_name IN VARCHAR2,
     wt_clusters   IN OUT VARCHAR2,
     wt_undir      IN OUT VARCHAR2,
     wt_cluas      IN OUT VARCHAR2,
     wt_newas      IN OUT VARCHAR2,
     wt_delta      IN OUT VARCHAR2,
     dop           IN INTEGER DEFAULT 4,
     rounds        IN INTEGER DEFAULT 0,
     tbs           IN VARCHAR2 DEFAULT NULL,
     options       IN VARCHAR2 DEFAULT NULL);

Description

Finds connected components in a property graph. All connected components will be stored in the wt_clusters table. The original graph is treated as undirected.

Parameters

edge_tab_name

Name of the property graph edge table.

wt_clusters

A working table holding the final vertex cluster mappings. This table has two columns (VID NUMBER, CLUSTER_ID NUMBER). Column VID stores the vertex ID values, and column CLUSTER_ID stores the corresponding cluster ID values. Cluster ID values are long integers that can have gaps between them.

If an empty name is specified, a new table will be generated, and its name will be returned.

wt_undir

A working table holding an undirected version of the graph.

wt_cluas

A working table holding current cluster assignments.

wt_newas

A working table holding updated cluster assignments.

wt_delta

A working table holding changes ("delta") in cluster assignments.

dop

Degree of parallelism for the operation. The default is 4.

rounds

Maximum umber of iterations to perform in searching for connected components. The default value of 0 (zero) means that computation will continue until all connected components are found.

tbs

Name of the tablespace to hold the data stored in working tables.

options

Additional settings for the operation.

'PDML=T' enables parallel DML.

Usage Notes

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

Examples

The following example finds the connected components in a property graph named mypg.

DECLARE
  wtClusters   varchar2(200) := 'mypg_clusters';
  wtUnDir      varchar2(200);
  wtCluas      varchar2(200);
  wtNewas      varchar2(200);
  wtDelta      varchar2(200);
BEGIN
  opg_apis.find_clusters_prep('mypgGE$', wtClusters, wtUnDir,
      wtCluas, wtNewas, wtDelta, '');
  dbms_output.put_line('working tables names ' || wtClusters || ' '
|| wtUnDir || ' ' || wtCluas || ' '  || wtNewas    || ' '
|| wtDelta );

opg_apis.find_cc_mapping_based(''mypgGE$', wtClusters, wtUnDir,
      wtCluas, wtNewas, wtDelta, 8, 0, 'MYTBS', 'PDML=T');

--
-- logic to consume results in wtClusters
-- e.g.: 
-- select /*+ parallel(8) */ count(distinct cluster_id) 
--   from mypg_clusters;

-- cleanup all the working tables
  opg_apis.find_clusters_cleanup('mypgGE$', wtClusters, wtUnDir,
      wtCluas, wtNewas, wtDelta, '');

END;
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