Oracle® Data Mining Application Developer's Guide 11g Release 2 (11.2) Part Number E12218-06 |
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This chapter provides an overview of the PL/SQL, SQL, and Java interfaces to Oracle Data Mining.
This chapter contains the following sections:
The PL/SQL interface to Oracle Data Mining is implemented in three packages:
DBMS_DATA_MINING
, the primary interface to Oracle Data Mining
DBMS_DATA_MINING_TRANSFORM
, convenience routines for data transformation
The DBMS_DATA_MINING
package includes procedures for:
Creating, dropping, and renaming mining models
Applying a model to new data
Describing the model details
Creating costs and computing test metrics for a classification model
Exporting and importing models
The CREATE_MODEL
procedure creates a mining model. The attributes, transformations, rules, and other information internal to the model are returned by GET_MODEL_DETAILS
functions. You can also obtain information about mining models by querying data dictionary views, as described in "Data Mining Data Dictionary Views".
The APPLY
procedure creates a table with specific columns and populates the columns with mining results. The columns of this table vary based on the particular mining function and algorithm.
Note:
The Data Mining SQL functions, introduced in Oracle Database 10.2, are now generally the preferred method for applying Data Mining models. See "Data Mining SQL Functions".This package includes routines for transforming the data to make it suitable for mining. Since Oracle Data Mining supports Automatic Data Transformation (ADP), you will not need to use this package unless you want to implement specialized transformations.
You can supplement the ADP-generated transformations with additional transformations that you specify yourself, or you can elect to transform the data yourself instead of using ADP.
The routines in DBMS_DATA_MINING_TRANSFORM
are convenience routines to assist you in creating your own transformations. If these routines do not entirely suit your needs, you can write SQL to modify their output, or you can write your own routines.
To specify transformations for a model, pass a transformation list to the DBMS_DATA_MINING.CREATE_MODEL
procedure. You can use the STACK
procedures in DBMS_DATA_MINING_TRANSFORM
to build the transformation list.
Oracle Data Mining embeds automatic transformations and transformations you pass to CREATE_MODEL
in the model. The embedded transformations are automatically applied to the data when the model is applied. You do not need to separately transform the test or scoring data.
See Also:
DBMS_DATA_MINING_TRANSFORM
in Oracle Database PL/SQL Packages and Types Reference
Oracle Data Mining Concepts for information about automatic and embedded data transformation
This package includes routines for predictive analytics, an automated form of data mining. With predictive analytics, you do not need to be aware of model building or scoring. All mining activities are handled internally by the predictive analytics procedure.
Predictive analytics routines prepare the data, build a model, score the model, and return the results of model scoring. Before exiting, they delete the model and supporting objects.
Oracle predictive analytics supports these routines:
You can obtain information about mining models from the data dictionary. The data dictionary views for Oracle Data Mining are available for ALL_
, USER_
, and DBA_
access.
The Data Mining data dictionary views are summarized as follows:
ALL_MINING_MODELS
returns information about the mining models to which you have access.
ALL_MINING_MODEL_ATTRIBUTES
returns information about the attributes of the mining models to which you have access.
See "About Attributes".
ALL_MINING_MODEL_SETTINGS
returns information about the settings for the mining models to which you have access.
See "Model Settings".
The built-in SQL functions for Data Mining implement scoring operations for models that have already been created in the database. They provide the following benefits:
Models can be easily deployed within the context of existing SQL applications.
Scoring operations take advantage of existing query execution functionality. This provides performance benefits, especially in the case of single row scoring.
Scoring results are pipelined, enabling the rows to be returned iteratively as they are produced. Pipelining is an optimization that greatly improves performance. For information about pipelining, see Oracle Database PL/SQL Language Reference.
Note:
SQL functions are built into Oracle Database and are available for use within SQL statements. SQL functions should not be confused with functions defined in PL/SQL packages.When applied to a given row of scoring data, classification and regression models provide the best predicted value for the target and the associated probability of that value occurring. The SQL functions for prediction are described in Table 2-1.
Table 2-1 SQL Functions for Prediction
Applying a cluster model to a given row of scoring data returns the cluster ID and the probability of that row's membership in the cluster. The SQL functions for clustering are described in Table 2-2.
Table 2-2 SQL Functions for Clustering
Function | Description |
---|---|
Returns the ID of the predicted cluster |
|
Returns the probability of a case belonging to a given cluster |
|
Returns a list of all possible clusters to which a given case belongs along with the associated probability of inclusion |
Applying a feature extraction model involves the mapping of features (sets of attributes) to columns in the scoring data set. The SQL functions for feature extraction are described in Table 2-3.
Table 2-3 SQL Functions for Feature Extraction
Function | Description |
---|---|
Returns the ID of the feature with the highest coefficient value |
|
Returns a list of objects containing all possible features along with the associated coefficients |
|
Returns the value of a given feature |
See Also:
Chapter 6, "Scoring and Deployment"The Oracle Data Mining Java API is an Oracle implementation of the JDM standard (JSR-73) Java API. It is a thin API developed using the rich in-database functionality of Oracle Data Mining.
The Oracle Data Mining Java API implements Oracle specific extensions to provide all the data mining features available in the database. All extensions are designed to be compliant with the JDM standards extension framework. All the mining functions and algorithms available in the database are exposed through the Oracle Data Mining Java API.
Oracle Database 10.2.0.1 introduced the JDM 1.0 standard compliant API that replaced the old Oracle proprietary Java API in the previous releases. Database 10.2.0.2 patch-set release extended the JDM standards support by implementing Oracle Data Mining Java API compatible with JDM 1.1.
In this release, the Oracle Data Mining Java API continues to be compatible with the JDM 1.1 and provides new data mining functionality in the database server as Oracle extensions. In this release new Oracle features include automatic and embedded data preparation, generalized linear models, transformation sequencing and task dependency specifications.
See Also:
Oracle Data Mining Concepts for a summary of the new features in the Oracle Data Mining Java APIJDM is an industry standard Java API for data mining developed under the Java Community Process (JCP). It defines Java interfaces that vendors can implement for their Data Mining Engine (DME). It includes interfaces supporting mining functions such as classification, regression, clustering, attribute importance and association along with specific mining algorithms such as naïve bayes, support vector machines, decision trees, feed forward neural networks, and k-means.
An overview of the Java packages defined by the standards is listed in Table 2-4. For more details, refer to the Java documentation published with the standard at http://www.jcp.org
. In the Go to JSR box, type in 73
.
Table 2-4 JDM Standard Java Packages
Package | Description |
---|---|
javax.datamining |
Defines objects supporting all JDM subpackages. |
javax.datamining.base |
Defines objects supporting many top-level mining objects. Introduced to avoid cyclic package dependencies. |
javax.datamining.resource |
Defines objects that support connecting to the Data Mining ENgine and executing tasks. |
javax.datamining.data |
Defines objects supporting logical and physical data, model signature, taxonomy, category set and the generic super class category matrix. |
javax.datamining.statistics |
Defines objects supporting attribute statistics. |
javax.datamining.rules |
Defines objects supporting rules and their predicate components. |
javax.datamining.task |
Defines objects supporting tasks for build, compute statistics, import, and export. Task has an optional subpackage for apply since apply is used mainly for supervised and clustering functions. |
javax.datamining.association |
Defines objects supporting the build settings and model for association. |
javax.datamining.clustering |
Defines objects supporting the build settings and model for clustering. |
javax.datamining.attributeimportance |
Defines objects supporting the build settings and model for attribute importance. |
javax.datamining.supervised |
Defines objects supporting the build settings and models for supervised learning functions, specifically classification and regression, with corresponding optional packages. It also includes a common test task for the classification and regression functions. |
javax.datamining.algorithm |
Defines objects supporting the settings that are specific to algorithms. The algorithm package has optional sub packages for different algorithms. |
javax.datamining.modeldetail |
Defines objects supporting details of various model representation. Model Details has optional sub packages for different model details. |
Oracle extensions are defined to support the functionality that is not part of the JDM standards. This section gives an overview of these extensions.
See Also:
Oracle Data Mining Java API Reference (javadoc).Oracle extensions have the following major additional features:
Feature Extraction function with the Non-negative Matrix Factorization (NMF) algorithm
Generalized Linear Model algorithm for regression and classification functions
Oracle-proprietary clustering algorithm, Orthogonal Partitioning Clustering (O-CLuster)
Oracle-proprietary classification algorithm, Adaptive Bayes Network (ABN) (deprecated)
Automated and embedded data transformations
Predictive analytics tasks
An overview of the Oracle extensions higher-level Java packages is provided in Table 2-5.
Table 2-5 Oracle Extensions Higher-Level Packages
Package | Description |
---|---|
oracle.dmt.jdm.featureextraction |
Defines the objects related to the feature extraction function. Feature extraction supports the scoring operation. |
oracle.dmt.jdm.algorithm.nmf |
Defines the objects related to the Non-negative Matrix Factorization (NMF) algorithm. |
oracle.dmt.jdm.algorithm.glm oracle.dmt.jdm.modeldetail.glm |
Defines the objects related to the Generalized Linear Model (GLM) algorithm. |
oracle.dmt.jdm.algorithm.ocluster |
Defines the objects related to the Orthogonal Clustering (O-Cluster) algorithm. |
oracle.dmt.jdm.algorithm.abn |
Defines the objects related to the Adaptive Bayes Network (ABN) algorithm (deprecated). |
oracle.dmt.jdm.transform |
Defines the objects related to the transformations. |
In JDM, named objects are objects that can be saved using the save method in the Connection. All the named objects are inherited from the javax.datamining.MiningObject
interface. You can choose to persist the named objects either permanently (persistent objects) or only for the lifetime of the Connection object (transient objects).
Table 2-6 lists the JDM named objects supported by Oracle Data Mining.
Table 2-6 JDM Named Objects Supported by Oracle Data Mining
Persistent Objects | Transient Objects | Unsupported Objects |
---|---|---|
Model |
Apply Settings |
Logical Data |
Build Settings |
Physical Dataset |
Taxonomy |
Task |
||
Cost Matrix |
||
Test Metrics |
||
Transformation sequence |
Physical data sets refer to the data to be used as input to data mining operations. PhysicalDataSet objects reference specific data identified by a URI. Oracle Data Mining supports a table or view in the same database as a valid physical dataset URI. Syntax of the physical dataset URI is as follows:
Data URI Syntax:
[schemaName.] tableName/viewName
The PhysicalDataSet object can support multiple data representations. Oracle Data Mining supports two types of data representation: single-record case and wide data. (See Chapter 3 for details.) The Oracle Data Mining implementation requires users to specify the case ID column in the physical dataset.
A PhysicalDataSet object is a transient object in the Oracle Data Mining Java API. It is stored in the Connection as an in-memory object.
A BuildSettings object captures the high-level specification input for building a model. The API specifies mining functions: classification, regression, attribute importance, association, clustering, and feature extraction.
Build settings allow a user to specify the type of result desired without having to specify a particular algorithm. Although a build settings object allows for the specification of an algorithm and its settings, if the algorithm settings are omitted, the DME selects an algorithm based on the build settings and possibly characteristics of the data.
Build settings may also be validated for correct parameters using the verify method.
A BuildSettings object is persistent; it is stored as a table with a user-specified name in the user's schema. This settings table is interoperable with the PL/SQL API. Oracle recommends that you not modify the build settings table manually.
The Execute method in the Connection object is used to start an execution of a mining task. Typically, mining operations are done using tables with millions of records, so the execution of operations such as a model build can take a long time.
JDM supports asynchronous execution of mining tasks using DBMS_SCHEDULER
in the database. Each mining task is stored as a DBMS_SCHEDULER
job object in the user's schema. When the user saves the task object, it creates a job object and sets the object to be in the DISABLED
state. When the user executes a task, it enables the job to start execution.
To monitor tasks that are executed asynchronously, the Execute method returns a javax.datamining.ExecutionHandle
object. It provides methods such as waitForCompletion
and getStatus
to retrieve the status details of the task.
A Model object is the result of applying an algorithm to data as specified in a BuildSettings object.
Models can be used in several operations. They can be:
Inspected, for example to examine the rules produced from a decision tree or association
Tested for accuracy
Applied to data for scoring
Exported to an external representation such as native format or PMML
When a model is applied to data, it is submitted to the DME for interpretation. A Model object references its BuildSettings
object as well as the Task
that created it. as.
A TestMetrics object is the result of testing a supervised model with test data. Based on the type of mining function, different test metrics are computed. For classification models, accuracy, confusion-matrix, lift, and receiver-operating characteristic can be computed to access the model. Similarly for regression models, R-squared and RMS errors can be computed.
An ApplySettings object allows users to tailor the results of an apply task. It contains a set of ordered items. Output can consist of:
Data (key attributes) to be passed through to the output from the input dataset.
Values computed from the apply itself: score, probability, and in the case of decision trees, rule identifiers.
Multi-class categories for its associated probabilities. For example, in a classification model with target favoriteColor, users could select the specific colors to receive the probability that a given color is favorite.
Each mining function class defines a method to construct a default apply settings object. This simplifies the programmer's effort if only standard output is desired. For example, typical output for a classification apply would include the top prediction and its probability.
A TransformationSequence object represents the sequence of transformations that are to be performed as part of a mining operation. For example, a Support Vector Machine model build involves outlier handling and normalization transformations. In addition to this, there can be new derived attribute creation and business transformations, and so on. Typically these transformations are reused for other model builds and hence applications can save the transformation sequence as a named object in the API.
Transformation sequences can be used either to perform transformations as a separate task or embed them to the modeling process by specifying it as one of the input objects for model building.