Hi,
Andrew Poodle Wrote:
-------------------------------------------------------
> Been thinking about partitioning and clustering..
>
> How does one specify which storage nodes the
> various partitions sit on?
> I can see how to specify disks, or physical
> locations, but not nodes.
>
It isn't possible to place partitions on nodes, it is however
possible to store partitions on NODEGROUPs. The reason is that
a partition must be on all nodes in a node group so it doesn't
make sense to specify only a node, one must specify the node
group.
Node groups are formed implicitly from the configuration. The
first NoReplica nodes are placed into first and so forth. The
first NODEGROUP is 0. You can check node group id's in a running
cluster with the show command in the management client.
An example to specify node groups in a table is:
CREATE TABLE (a int primary key, b int)
PARTITION BY KEY (a)
(PARTITION p0 NODEGROUP 1);
This will create a table with only one partition in the second node group.
Regarding where data is stored the usual mechanics apply.
Data is not replicated between node groups but is fully replicated
within a node group.
Rgrds Mikael
> And since 5.1.6, cluster supports disk based data
> storage, but the indexed and PK columns are in
> memory.
>
> IF the table is partitioned, does only the
> relevant section of the partitioned data reside in
> memory on it's related storage node, or do the
> indexes and keys exist in their entirity in memory
> on each node?
>
> a
Mikael Ronstrom
Senior Software Architect, MySQL AB
My blog:
http://mikaelronstrom.blogspot.com