Monday, January 30, 2017

Slides from the OUG Ireland meet-ups

I've finally gotten the time (and the permissions from the presenters) to make the slides from the first two OUG Ireland meet-ups available.

I've posted them on SlideShare and I've embedded them in this blog post too.


Thursday, January 26, 2017

Formatting results from ORE script in a SELECT statement

This blog post looks at how to format the output or the returned returns from an Oracle R Enterprise (ORE), user defined R function, that is run using a SELECT statement in SQL.

Sometimes this can be a bit of a challenge to work out, but it can be relatively easy once you have figured out how to do it. The following examples works through some scenarios of different results sets from a user defined R function that is stored in the Oracle Database.

To run that user defined R function using a SELECT statement I can use one of the following ORE SQL functions.

  • rqEval
  • rqTableEval
  • "rqGroupEval"
  • rqRowEval

For simplicity we will just use the first of these ORE SQL functions to illustrate the problem and how to go about solving it. The rqEval ORE SQL function is a generate purpose function to call a user defined R script stored in the database. The function does not require any input data set and but it will return some data. You could use this to generate some dummy/test data or to find some information in the database. Here is noddy example that returns my name.

BEGIN
   --sys.rqScriptDrop('GET_NAME');
   sys.rqScriptCreate('GET_NAME',
      'function() {
         res<-data.frame("Brendan")
         res
         } ');
END;

To call this user defined R function I can use the following SQL.

select *
from table(rqEval(null,
                  'select cast(''a'' as varchar2(50))  from dual',
                  'GET_NAME') );  

For text strings returned you need to cast the returned value giving a size.

If we have a numeric value being returned we can don't have to use the cast and instead use '1' as shown in the following example. This second example extends our user defined R function to return my name and a number.

BEGIN
   sys.rqScriptDrop('GET_NAME');
   sys.rqScriptCreate('GET_NAME',
      'function() {
         res<-data.frame(NAME="Brendan", YEAR=2017)
         res
         } ');
END;

To call the updated GET_NAME function we now have to process two returned columns. The first is the character string and the second is a numeric.

select *
from table(rqEval(null,
                  'select cast(''a'' as varchar2(50)) as "NAME", 1 AS YEAR  from dual',
                  'GET_NAME') );                  

These example illustrate how you can process character strings and numerics being returned by the user defined R script.

The key to setting up the format of the returned values is knowing the structure of the data frame being returned by the user defined R script. Once you know that the rest is (in theory) easy.

Monday, January 23, 2017

Oracle Data Miner 4.2 New Features

Oracle Data Miner 4.2 (part of SQL Developer 4.2) got released as an Early Adopter versions (EA) a few weeks ago.

I had an earlier blog post that looked that the new Oracle Advanced Analytics in-database new features with the Oracle 12.2 Database.

With the new/updated Oracle Data Miner (ODMr) there are a number of new features. These can be categories as 1) features all ODMr users can use now, 2) New features that are only usable when using Oracle 12.2 Database, and 3) Updates to existing algorithms that have been exposed via the ODMr tool.

The following is a round up of the main new features you can enjoy as part of ODMr 4.2 (mainly covering points 1 and 2 above)

  • You can now schedule workflows to run based on a defined schedule
  • Support for additional data types (RAW, ROWID, UROWID, URITYPE)
  • Better support for processing JSON data in the JSON Query node
  • Additional insights are displayed as part of the Model Details View
  • Additional alert monitoring and reporting
  • Better support for processing in-memory data
  • A new R Model node that allows you to include in-database ORE user defined R function to support model build, model testing and applying of new model.
  • New Explicit Semantic Analysis node (Explicit Feature Extraction)
  • New Feature Compare and Test nodes
  • New workflow status profiling perfoance improvements
  • Refresh the input data definition in nodes
  • Attribute Filter node now allows for unsupervised attribute importance ranking
  • The ability to build Partitioned data mining models

Look out for the blog posts on most of these new features over the coming months.

WARNING: Most of these new features requires an Oracle 12.2 Database.

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Monday, January 16, 2017

Explicit Semantic Analysis setup using SQL and PL/SQL

In my previous blog post I introduced the new Explicit Semantic Analysis (ESA) algorithm and gave an example of how you can build an ESA model and use it. Check out this link for that blog post.

In this blog post I will show you how you can manually create an ESA model. The reason that I'm showing you this way is that the workflow (in ODMr and it's scheduler) may not be for everyone. You may want to automate the creation or recreation of the ESA model from time to time based on certain business requirements.

In my previous blog post I showed how you can setup a training data set. This comes with ODMr 4.2 but you may need to expand this data set or to use an alternative data set that is more in keeping with your domain.

Setup the ODM Settings table

As with all ODM algorithms we need to create a settings table. This settings table allows us to store the various parameters and their values, that will be used by the algorithm.

-- Create the settings table
CREATE TABLE ESA_settings (
    setting_name VARCHAR2(30),
    setting_value VARCHAR2(30));

-- Populate the settings table
-- Specify ESA. By default, Naive Bayes is used for classification.
-- Specify ADP. By default, ADP is not used. Need to turn this on.
BEGIN
    INSERT INTO ESA_settings (setting_name, setting_value)
    VALUES (dbms_data_mining.algo_name,       
           dbms_data_mining.algo_explicit_semantic_analys);
   
    INSERT INTO ESA_settings (setting_name, setting_value)
    VALUES (dbms_data_mining.prep_auto,dbms_data_mining.prep_auto_on);
  
    INSERT INTO ESA_settings (setting_name, setting_value)
    VALUES (odms_sampling,odms_sampling_disable);
  
    commit;
END; 

These are the minimum number of parameter setting needed to run the ESA algorithm. The other ESA algorithm setting include:

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Setup the Oracle Text Policy

You also need to setup an Oracle Text Policy and a lexer for the Stopwords.

DECLARE
   v_policy_name  varchar2(30);
   v_lexer_name   varchar2(3)
BEGIN
    v_policy_name  := 'ESA_TEXT_POLICY';
    v_lexer_name   := 'ESA_LEXER';
    ctx_ddl.create_preference(v_lexer_name, 'BASIC_LEXER');
    v_stoplist_name := 'CTXSYS.DEFAULT_STOPLIST';  -- default stop list
    ctx_ddl.create_policy(policy_name => v_policy_name, lexer => v_lexer_name, stoplist => v_stoplist_name);
END;

Create the ESA model

Once we have the settings table created with the parameter values set for the algorithm and the Oracle Text policy created, we can now create the model.

To ensure that the Oracle Text Policy is applied to the text we want to analyse we need to create a transformation list and add the Text Policy to it.

We can then pass the text transformation list as a parameter to the CREATE_MODEL, procedure.

DECLARE
   v_xlst              dbms_data_mining_transform.TRANSFORM_LIST;
   v_policy_name       VARCHAR2(130) := 'ESA_TEXT_POLICY';
   v_model_name        varchar2(50) := 'ESA_MODEL_DEMO_2';
BEGIN
   v_xlst := dbms_data_mining_transform.TRANSFORM_LIST();
   DBMS_DATA_MINING_TRANSFORM.SET_TRANSFORM(v_xlst, '"TEXT"', NULL, '"TEXT"', '"TEXT"', 'TEXT(POLICY_NAME:'||v_policy_name||')(MAX_FEATURES:3000)(MIN_DOCUMENTS:1)(TOKEN_TYPE:NORMAL)');

    DBMS_DATA_MINING.DROP_MODEL(v_model_name, TRUE);
    DBMS_DATA_MINING.CREATE_MODEL(
        model_name          => v_model_name,
        mining_function     => DBMS_DATA_MINING.FEATURE_EXTRACTION,
        data_table_name     => 'WIKISAMPLE',
        case_id_column_name => 'TITLE',
        target_column_name  => NULL,
        settings_table_name => 'ESA_SETTINGS',
        xform_list          => v_xlst);
END;

NOTE: Yes we could have merged all of the above code into one PL/SQL block.

Use the ESA model

We can now use the FEATURE_COMPARE function to use the model we just created, just like I did in my previous blog post.
SELECT FEATURE_COMPARE(ESA_MODEL_DEMO_2
               USING 'Oracle Database is the best available for managing your data' text 
               AND USING 'The SQL language is the one language that all databases have in common' text) similarity 
FROM DUAL;

Go give the ESA algorithm a go and see where you could apply it within your applications.

Monday, January 9, 2017

next OUG Ireland Meet-up on 12th January

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Our next OUG Ireland Meet-up with be on Thursday 12th January, 2017.
The theme for this meet up is DevOps and How to Migrate to the Cloud.
Come along on the night here about these topics and how companies in Ireland are doing these things.
Venue : Bank of Ireland, Grand Canal Dock, Dublin.
The agenda for the meet-up is:
18:00-18:20 Sign-in, meet and greet, networking, grab some refreshments, etc
18:20-18:30 : Introductions & Welcome, Agenda, what is OUG Ireland, etc.
18:30-19:00 : Dev Ops and Oracle PL/SQL development - Alan McClean
Abstract
In recent years the need to deliver changes to production as soon as possible has led to the rise of continuous delivery; continuous integration and continuous deployment. These issues have become standards in the application development, particularly for code developed in languages such as Java. However, database development has lagged behind in supporting this paradigm. There are a number of steps that can be taken to address this. This presentation examines how database changes can be delivered in a similar manner to other languages. The presentation will look at unit testing frameworks, code reviews and code quality as well as tools for managing database deployment.
19:00-1930 : Simplifying the journey to Oracle Cloud : Decision makers across Managers, DBA’s and Cloud Architects who need to progress an Oracle Cloud Engagement in the organization - Ken MacMahon, Head of Oracle Cloud Services at Version1
Abstract
The presentation will cover the 5 steps that Version 1 use to try and help customers with Oracle Cloud adoption in the organisation. By attending you will hear, how to deal with cloud adoption concerns, choose candidates for cloud migration, how to design the cloud architecture, how to use automation and agility in your Cloud adoption plans, and finally how to manage your Cloud environment.

This event is open to all, you don't have to be a member of the user group and best of all it is a free event. So spread the word with all your Oracle developer, DBAs, architects, data warehousing, data vizualisations, etc people.
We hope you can make it! and don't forget to register for the event.
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Wednesday, January 4, 2017

Explicit Semantic Analysis in Oracle 12.2c Database

A new Oracle Data Mining algorithm in the Oracle 12.2c Database is called Explicit Semantic Analysis.

[The following examples are built using Oracle Data Miner 4.2 (SQL Developer 4.2) and the Oracle 12.2 Database cloud service (extreme edition) ]

The Explicit Semantic Analysis algorithm is an unsupervised algorithm used for feature extraction. ESA does not discover latent features but instead uses explicit features based on an existing knowledge base. There is no setup or install necessary to use this algorithm All you need is a licence for the Advanced Analytics Option for the database. The out from the algorithm is a distance measure that indicates how similar or dis-similar the input texts are, using the ESA model (and the training data set used). Let us look at an example. Setup training data for ESA Algorithm

Oracle Data Miner 4.2 (that comes with SQL Developer 4.2) has a data Wiki data set from 2005. This contains over 200,000 features. To locate the file go to.

...\sqldeveloper\dataminer\scripts\instWikiSampleData.sql

This file contains the DDL and the insert statements for the Wiki data set.

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After you run this script a new table called WIKISAMPLE table exists and contains records

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This gives us the base/seed data set to feed into the ESA algorithm.

Create the ESA Model using ODMr

To create the ESA model we have 2 ways of doing this. In this blog post I'll show you the easiest way by using the Oracle Data Miner (ODMr) tool. I'll have another blog post that will show you the SQL needed to create the model.

In an ODMr workflow create a new Data Source node. Then set this node to have the WIKISAMPLE table as it's data source.

Next you need to create the ESA node on the workflow. This node can be found in the Models section, of the Workflow Editor. The node is called Explicit Feature Extraction. Click on this node, in the model section, and then move your mouse to your workflow and click again. The ESA node will be created.

Join the Data Node to the ESA node by right clicking on the data node and then clicking on the ESA node.

Double click on the ESA node to edit the properties of the node and the algorithm.

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Explore the ESA Model and ESA Model Features

After the model node has finished you can now explore the results generated by the ESA model. Right click on the model node and select 'View Model'. The model properties window opens and it has 2 main tabs. The first of these is the coefficients tab. Here you can select a particular topic (click on the search icon beside the Feature ID) and select it from the list. The attributes and their coefficient values will be displayed.

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Next you can examine the second tab that is labeled as Features. In this table we can select a particular record and have a tag cloud and coefficients displayed. The tag cloud is a great way to see visually what words are important.

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How to use the ESA model to Compare new data using SQL

Now that we have the ESA model created, we can not use it model to compare other similar sets of documents.

You will need to use the FEATURE_COMPARE SQL function to evaluate the input texts, using the ESA model to compare for similarity. For example,

SELECT FEATURE_COMPARE(feat_esa_1_1
          USING 'Oracle Database is the best available for managing your data' text 
          AND USING 'The SQL language is the one language that all databases have in common' text) similarity 
FROM DUAL;
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The result we get is 0.7629.

The result generate by the query is a distance measure. The FEATURE_COMPARE function returns a comparison number in the range 0 to 1. Where 0 indicates that the text are not similar or related. If a 1 is returned then that indicated that the text are very similar or very related.

You can use this returned value to make a decision on what happens next. For example, it can be used to decide what the next step should be in your workflow and you can easily write application logic to manage this.

The examples given here are for general text. In the real world you would probably need a bigger data set. But if you were to use this approach in other domains, such as legal, banking, insurance, etc. then you would need to create a training data set based on the typical language that is used in each of those domains. This will then allow you to compare documents with each domain with greater accuracy.

[The above examples are built using Oracle Data Miner 4.2 (SQL Developer 4.2) and the Oracle 12.2 Database cloud service (extreme edition) ]