Administration Guide

Creating Nodegroups

You create a nodegroup with the CREATE NODEGROUP statement. This statement specifies the set of nodes on which the table space containers and table data are to reside. This statement also:

• Creates a partitioning map for the nodegroup. For details about the partitioning map, see Partitioning Maps.
• Generates a partitioning map ID.
• Inserts records into the following catalog tables:
  • SYSCAT.NODEGROUPS
  • SYSCAT.PARTITIONMAPS
  • SYSCAT.NODEGROUPDEF

To create a nodegroup using the Control Center:

Expand the object tree until you see the Nodegroups folder. Right-click the Nodegroups folder, and select Create from the pop-up menu. On the Create Nodegroups window, complete the information, use the arrows to move nodes from the Available nodes box to the Selected nodes box, and click Ok.

To create a nodegroup using the command line, enter:

   CREATE NODEGROUP <name> ON NODES (<value>,<value>)

Assume that you want to load some tables on a subset of the database partitions in your database. You would use the following command to create a nodegroup of two nodes (1 and 2) in a database consisting of at least three (0 to 2) nodes:

  CREATE NODEGROUP mixng12 ON NODES (1,2)

For more information about creating nodegroups, refer to the SQL Reference manual.

The CREATE DATABASE command or sqlecrea() API also create the default system nodegroups, IBMDEFAULTGROUP, IBMCATGROUP, and IBMTEMPGROUP. (See Designing and Choosing Table Spaces for information.)