38.10 FEATURE_VALUE
Syntax
feature_value::=
Analytic Syntax
feature_value_analytic::=
mining_attribute_clause::=
mining_analytic_clause::=
See Also:
"Analytic Functions" for information on the syntax, semantics, and restrictions of mining_analytic_clause
Purpose
FEATURE_VALUE
returns a feature value for each row in the selection. The value refers to the highest value feature or to the specified feature_id
. The feature value is returned as BINARY_DOUBLE
.
Syntax Choice
FEATURE_VALUE
can score the data in one of two ways: It can apply a mining model object to the data, or it can dynamically mine the data by executing an analytic clause that builds and applies one or more transient mining models. Choose Syntax or Analytic Syntax:
-
Syntax — Use the first syntax to score the data with a pre-defined model. Supply the name of a feature extraction model.
-
Analytic Syntax — Use the analytic syntax to score the data without a pre-defined model. Include
INTO
n
, wheren
is the number of features to extract, andmining_analytic_clause
, which specifies if the data should be partitioned for multiple model builds. Themining_analytic_clause
supports aquery_partition_clause
and anorder_by_clause
. (See "analytic_clause::=".)
The syntax of the FEATURE_VALUE
function can use an optional GROUPING
hint when scoring a partitioned model. See GROUPING Hint.
mining_attribute_clause
mining_attribute_clause
identifies the column attributes to use as predictors for scoring. When the function is invoked with the analytic syntax, this data is also used for building the transient models. The mining_attribute_clause
behaves as described for the PREDICTION
function. (See "mining_attribute_clause".)
See Also:
-
Oracle Data Mining User's Guide for information about scoring.
-
Oracle Data Mining Concepts for information about feature extraction.
Note:
The following example is excerpted from the Data Mining sample programs. For more information about the sample programs, see Appendix A in Oracle Data Mining User's Guide.
Example
The following example lists the customers that correspond to feature 3, ordered by match quality.
SELECT * FROM (SELECT cust_id, FEATURE_VALUE(nmf_sh_sample, 3 USING *) match_quality FROM nmf_sh_sample_apply_prepared ORDER BY match_quality DESC) WHERE ROWNUM < 11; CUST_ID MATCH_QUALITY ---------- ------------- 100210 19.4101627 100962 15.2482251 101151 14.5685197 101499 14.4186292 100363 14.4037396 100372 14.3335148 100982 14.1716545 101039 14.1079914 100759 14.0913761 100953 14.0799737