Appendix A: System Procedures

sp_text_cluster

Description

Displays or changes clustering parameters for the active thread.

Syntax

sp_text_cluster server_name, cluster_parameter [, cluster_value]

Parameters

server_name: is the name of the Enhanced Full-Text Search engine.

cluster_parameter: is the name of the clustering parameter. Values are shown in Table A-2.

cluster_value

is the value you assign to the clustering parameter for the active thread. Values are shown in Table A-2.

**Table A-2: Clustering configuration parameters**
Values for cluster_parameter	Values for cluster_value
cluster_style	Specifies the type of clustering to use. Valid values are: fixed – generates a fixed number of clusters. The number is set by the cluster_max parameter. coarse – automatically determines the number of clusters to generate, based on fewer, coarse grained clusters. medium – automatically determines the number of clusters to generate, based on medium-sized clusters. fine – automatically determines the number of clusters to generate, based on smaller, finer-grained clusters.
cluster_max	Specifies the maximum number of clusters to generate when cluster_style is set to fixed. A value of 0 means that the search engine determines the number of clusters to generate.
cluster_effort	Specifies the amount of effort (time) that the search engine should expend on finding a good clustering. Valid values are: effort_default – the search engine spends the default amount of time. You can also use the Verity term “default” if you enclose it in double quotes (“ ”). high – the search engine spends the longest time. medium – the search engine spends less time. low – the search engine spends the least amount of time.
cluster_order	Specifies the order in which to return the rows within the clusters. Valid values are: "0" – indicates rows are returned in order of similarity to the cluster center. This means the first row returned for a cluster is the one that is most prototypical of the rows in the cluster. "1" – indicates that rows are returned in the same relative order in which they were submitted for clustering. For example, if cluster 1 contains the first, third and seventh rows found for the query, they will be returned in that relative order within the cluster.

Examples

Example 1

sp_text_cluster KRAZYKAT, cluster_order, "1"

Changes the cluster_order parameter to 1 for the active thread.

Example 2

sp_text_cluster KRAZYKAT, cluster_style

Displays the current value of the cluster_style parameter.

Usage

The Verity clustering algorithm attempts to group similar rows together, based on the values of the clustering parameters.
If you specify the cluster_parameter parameter, but omit the the cluster_value parameter, sp_text_cluster displays the value of the clustering parameter that is specified.
sp_text_cluster does not modify the value of the clustering configuration parameter. The cluster_value is valid only for the thread that is currently executing. To modify the default values, use sp_text_configure.
For information on how to request a clustered result set, see “Using pseudo columns to request clustered result sets”.

Messages

This procedure is not supported against remote server ‘server_name.’
The parameter value ‘value’ is invalid.
sp_text_cluster failed (status = status).

Permissions

Any user can execute sp_text_cluster.