SET_CONTROL_SET_SIZE

Sets the number of control nodes that participate in the spread service when large cluster is enabled. If the database is running in Enterprise Mode, this function sets the number of control nodes for the entire database cluster. If the database is running in Eon Mode, this function sets the number of control nodes in the subcluster you specify. See Large cluster for more information.

This is a meta-function. You must call meta-functions in a top-level SELECT statement.

Behavior type

Syntax

In Enterprise Mode:

SET_CONTROL_SET_SIZE( control_nodes )

In Eon Mode:

SET_CONTROL_SET_SIZE('subcluster_name', control_nodes )

Parameters

subcluster_name

The name of the subcluster where you want to set the number of control nodes. Only allowed when the database is running in Eon Mode.

control_nodes

The number of control nodes to assign to the cluster (when in Enterprise Mode) or subcluster (when in Eon Mode). Value can be one of the following:

• Positive integer value: Vertica assigns the number of control nodes you specify to the cluster or subcluster. This value can be larger than the current node count. This value cannot be larger than 120 (the maximum number of control nodes for a database). In Eon Mode, the total of this value plus the number of control nodes set for all other subclusters cannot be more than 120.

• -1: Makes every node in the cluster or subcluster into control nodes. This value effectively disables large cluster for the cluster or subcluster.

Privileges

Examples

In an Enterprise Mode database, set the number of control nodes for the entire cluster to 5:

=> SELECT set_control_set_size(5);
 SET_CONTROL_SET_SIZE
----------------------
 Control size set
(1 row)

See also

• Changing the number of control nodes and realigning