[MADLIB-1253] Pagerank grouping does not give any output on complete graphs

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: v1.15
• Component/s: Module: Graph
• Assignee: Unassigned
• Reporter: Orhan Kislal
• Created: 13/Jul/18 22:53
• Updated: 17/Jul/18 22:00
• Resolved: 17/Jul/18 22:00

Description

If we use a completely connected graph with grouping, there is no output. Non-grouping calls do not have this issue.

CREATE TABLE vertex(
id INTEGER
);
CREATE TABLE edge_full(
src INTEGER,
dest INTEGER,
user_id INTEGER
);
INSERT INTO vertex VALUES
(0),
(1),
(2);
INSERT INTO edge_full VALUES
(0, 1, 1),
(0, 2, 1),
(1, 2, 1),
(2, 1, 1),
(1, 0, 1),
(2, 0, 1);

DROP TABLE IF EXISTS pagerank_grp_out_summary, pagerank_grp_out;
SELECT pagerank(
'vertex', -- Vertex table
'id', -- Vertix id column
'edge_full', -- "EDGE" table
'src=src, dest=dest', -- "EDGE" args
'pagerank_grp_out', -- Output table of PageRank
NULL, -- Default damping factor (0.85)
NULL, -- Default max iters (100)
NULL, -- Default Threshold
'user_id');

select * from pagerank_grp_out;
 user_id | id | pagerank
---------+----+----------
(0 rows)