Return nodes based on number of connections?

Posted Thu, 22/10/2009 - 21:03 by ca-uk

I've been looking at neo4j - how far off am i in thinking that this is a similar concept, but nicely packaged to fit into mysql?

I'm interested in finding proximity of nodes to each other - for example (all connections are bidirectional)

Server 1 <-> Server 2
Server 1 <-> Server 3
Server 3 <-> Server 4
Server 3 <-> Server 5
Server 5 <-> Server 6

What i would then like to do is say show me all servers that are 1 connection away - e.g. for server 1, then servers 2 & 3 are only 1 connection away. I'd also like to say show me all servers that are 2 connections away - e.g. for server 1, then servers 4 & 5 are two connections away (via node 3). I'd also like to be able to say show me all that are 1 or 2 connections away, i.e. 2,3,4,5 (for server 1)

Is this possible? How many connections from the origin point would this work for - as in some cases our servers may be interconnected over 8 connections.

Look forward to downloading it and trying it out. Also, congratulations on actually putting your support prices up for all to see - makes it much easier to see if it's worth investing the time looking at the product if we can see in advance how much support is likely to cost.

‹ OQGRAPH engine session on MySQL University (slides + AVrecording)

Returning select vertices.

by antony - 23 Oct 2009 - 06:22

It would be very possible to find vertices which are a specific distance away from a starting point with OQGRAPH. You simply need to construct something like the following query.

SELECT linkid FROM graph
WHERE latch=2 AND origid=1 AND ( weight=1 OR weight=2 )

for example:


mysql> CREATE TABLE graph (
-> latch SMALLINT UNSIGNED NULL,
-> origid BIGINT UNSIGNED NULL,
-> destid BIGINT UNSIGNED NULL,
-> weight DOUBLE NULL,
-> seq BIGINT UNSIGNED NULL,
-> linkid BIGINT UNSIGNED NULL,
-> KEY (latch, origid, destid) USING HASH,
-> KEY (latch, destid, origid) USING HASH
-> ) ENGINE=OQGRAPH;
Query OK, 0 rows affected (0.07 sec)

mysql> INSERT INTO graph (origid,destid) VALUES
-> (1,2),(2,1),
-> (1,3),(3,1),
-> (3,4),(4,3),
-> (3,5),(5,3),
-> (5,6),(6,5);
Query OK, 10 rows affected (0.00 sec)
Records: 10 Duplicates: 0 Warnings: 0

mysql> SELECT linkid FROM graph WHERE latch=2 AND origid=1 AND weight=1;
+--------+
| linkid |
+--------+
| 3 |
| 2 |
+--------+
2 rows in set (0.02 sec)

mysql> SELECT linkid FROM graph WHERE latch=2 AND origid=1 AND weight=2;
+--------+
| linkid |
+--------+
| 5 |
| 4 |
+--------+
2 rows in set (0.00 sec)

mysql> SELECT linkid FROM graph WHERE latch=2 AND origid=1 AND (weight=1 OR weight=2);
+--------+
| linkid |
+--------+
| 5 |
| 4 |
| 3 |
| 2 |
+--------+
4 rows in set (0.00 sec)

sounds like just the ticket -

by ca-uk - 24 Oct 2009 - 01:05

sounds like just the ticket - can't wait to get my sticky mitts on the plugin for mysql 5.1 to give it a go..