Hi, Data Node is where the data resides but no SQL functionality. SQL Nodes is a MySQL Server that gets data for queries from the Data Nodes. There can be several Data Nodes and several SQL Nodes in a cluster and each SQL node sees all data in all Data Nodes.

Rgrds Mikael PS: For more info check on-line MySQL Reference Manual

2006-01-23 kl. 19.08 skrev Dan Trainor:

Good morning, all -

I've been becoming increasingly familiar with how the MySQL Cluster operates, and I'm very, very excited. So excited, in fact, that we're doing heavy development on an application based upon it. However, there are still some loose ends which I'd like tied up.

I have searched the archives, and although I've found some responses that are close, I have not found an exact answer for what I'm looking for.

I understand the uses of (naturally) the mnanagement server and the data node. However, I don't understand where the SQL Server comes into play. Don't the data nodes just appear as large SQL Servers which participate in the cluster configuration?

I suppose it would make sense to have data nodse and SQL nodes if they were completely seperate beasts. I believe it would make sense for clients to query the SQL nodes instead of the data nodes, thus decreasing any load which may have applied to the data nodes. However, using an SQL server in this manner, wouldn't this defeat the purpose of the cluster as a whole?

Thanks for your time, it's much appreciated -Dan Trainor

Mikael Ronstrom, Senior Software Architect MySQL AB, www.mysql.com

Jumpstart your cluster: http://www.mysql.com/consulting/packaged/cluster.html My blog: http://mikaelronstrom.blogspot.com