Thursday, November 29, 2012

Association Rules in ODM-Part 3

This is a the third part of a four part blog post on building and using Association Rules in Oracle Data Miner. The following outlines the contents of each post in the series on Association Rules

  1. This first part will focus on how to building an Association Rule model
  2. The second post will be on examining the Association Rules produced by ODM – This blog post
  3. The third post will focus on using the Association Rules on your data.
  4. The final post will look at how you can do some of the above steps using the ODM SQL and PL/SQL functions.

In my previous posts I showed how you can go about setting up for Association Rule analysis in Oracle Data Miner and how to examine the rules that are generated.

This post will focus on how we can extract and use these rules in Oracle Data Miner.

Step 1 – Model Details

Association Rules are an unsupervised method of data mining. In Oracle Data Miner we cannot use the Apply node to to score new data. What we have to do is to generate the Model Details. These in turn can then be used.

The Model Details node is used when we do unsupervised learning to extract the rules that are generated.

To do this we need to click on the Model Details node in the Models section of the Component Palette and then click on our workspace, just to the right of the Association Rule node.

The Edit Model Selection window will open. Connect the Association Rule node to the Model Details node. Then Run the node. This will then generate the Association Rules in a format what we can reuse.

image

When you get the small green tick on the Model Details node you can then view what was generated.

Right click on the Model Details node and click on View Details from the menu.

image

The output is similar to what we would have seen under the Association Rule node with the addition of a few more attributes that include the schema name and model name.

We can order the rules based on the Confidence level by double clicking on the Confidence column header. You might need to do this twice to get the rule appearing based on a descending confidence value.

At this point we can no look at persisting the Association Rules. See step 2 below.

We can also view the SQL that was used to generate the Association Rules that we see in the Model Details node. While still viewing the rules, click on the SQL tab.

image

Step 2 – Persisting the Association Rules

To make the rules persist and be useable outside of ODM we can persist the Association Rules in a table. The first step to do this is to create a new Table Node. This can be found under the Data section of the Component Palette. Click this Create Table or View node in the component palette and then click on the workspace, just to the right of the Model Details node.

Connect the Model Details node to the Output node, by right clicking on the Model Details node, select Connect from the menu and then click on the Output Node.

We can now edit the format of the Output i.e. specify what attributes are to be in our Output table. Double click on the Output node or right click and select Edit from the menu. We now get the Edit Create Table or View Node.

SNAGHTML18801036

We can give the output a meaningful name e.g. AR_OUTPUT_RULES. We can also specify what rule properties we can to export to attributes in out table.

We will need to un-tick the Auto Input Columns Selection tick box before we can remove any of the output attributes. In my case I only want to have ANTECENDENT_ITEMS, CONSEQUENT_ITEMS, ID, LENGTH, CONFIDENCE and SUPPORT in my out put. So I need to select and highlight all the other attributes (holding the control button). After selecting all the attributes I do not want included in the final output table, I need to click on the red X icon.

SNAGHTML18859128

When complete click on the OK button to go back to the workflow.

To generate the table right click on the AR_OUTPUT_RULES node and select Run from the menu. When you get the green tick mark on the AR_OUTPUT_RULES node the table has been created with records containing the details of each rules.

image

To view the contents of the AR_OUTPUT_RULES table we can right click on this node and select view data from the menu.

image

We can now use these rules in our applications.

 

Check out the next post in the series (Part 4) where we will look at the functionality available in the ODM SQL & PL/SQL functions to perform Association Rule analysis.

Tuesday, November 27, 2012

Association Rules in ODM–Part 2

This is a the second part of a four part blog post on building and using Association Rules in Oracle Data Miner.  The following outlines the contents of each post in the series on Association Rules

  1. This first part will focus on how to building an Association Rule model
  2. The second post will be on examining the Association Rules produced by ODM – This blog post
  3. The third post will focus on using the Association Rules on your data.
  4. The final post will look at how you can do some of the above steps using the ODM SQL and PL/SQL functions. 

In the previous post I looked at the steps needed to setup a data source and to setup the Association Rule node. When everything was setup we ran the workflow.

Step 1 – Viewing the Model

We the workflow has finished running we will have the green tick marks on each node. This is where we left thing at the end of the previous post (Part 1). To view the model details, right click on the Association Role Node and select View Models from the menu.

image

There are 3 main concepts that are important in relation to Association Rules:

  • Support: is the proportion of transactions in the data set that contain the item set i.e. the number of times the rule occurs
  • Confidence: is the proportion of the occurrences of the antecedent that result in the consequent e.g. how many times do we get C when we have A and B  {A, B} => C
  • Lift: indicates the strength of a rule over the random co-occurrence of the antecedent and the consequent

Support and Confidence are the primary measures that are used to access the usefulness of an association rule.

In our example we can see that the the antecedent and the consequent has numbers separated by the word AND. These numbers correspond to the product numbers.

Step 2 – Examining the Model Rules

To read the antecedent and the consequent for the first rule in our example we have:

Antecedent: 137 AND 143 AND 128

Consequent: 144

To read this association rule we would say that if a Customer bought product 137 and product 143 and product 128, then we have a Confidence value of almost 71%. This is a strong association.

We can check the ordering of the rules by changing the Sort By criteria. As Confidence and Support are the main ways to evaluate the rules, we can change the Sort By criteria to be Confidence. Then click on the Query button to refresh the rules section.

image

Here get a list of the strongest rules listed in descending order.

Below the section of the screen that has the Rules, we have the Rule Details section.

image 

Here we can see that the rule gets formatted into an IF statement. The first rule in the list has a confidence of almost 97%. As it is a simple IF statement it can be easily implemented in our applications.

We want use the information that these rules provides in a number of ways. One such consequence of these rules is that we can look at improving the ordering and distribution of these products to ensure that we have sufficient numbers of each. Another consequence is that we can enhance the front end selling mechanism to make sure that if a customer is buying product 114, 118 and 115 then we can remind the customer of product 119. We can also ensure that all these products are not located beside each other, so that the customer will have to walk past many other products in order to find them. That is why we never see milk and bread beside each other in a grocery store.

Step 3 – Applying Filters to the Model Rules

In the previous step we were able to sort our rules based on some of the measures of our Association Rules and to see how these rules are structured.

Association Rule Analysis can generate many thousands of possible rules for a small data set. In some cases the similar rules can appear and we can have lots of rules that occur so infrequently that they are perhaps meaningless.

ODM provides us with a number of filters that we can apply to the rules that enables use to look for the rules that are of must interest to use. We can access these filters by clicking on the More button, that is located just under the Query button.

We can refine our query on the rules based on the various measures and the number if items in the rule. In addition to this we can also filter based on the values of the items. This is particularly useful if we want to concentrate on specific items (in our example Products). To illustrate this use focus on the rules that involve Product 115. Click on the green + symbol on the right hand side of the window. Select 115 from the list provided. Next we need to decide if we want Product 115 involved in the Antecedent or the Consequent. In our example select the Consequent. This is located to the bottom right of the window. Then click the OK button and then click on the Query button to update the list of rules that correspond with the new filter.

image

We can see that we only have rules that have Product 115 in the Consequent column.

We can also see that we have 134 rules for this scenarios out of a total of 20,988 (your results might differ slightly to mine and that’s OK. It really depends on what version of the sample data you are using)

 

Check out the next post in the series (Part 3) where we will look at how you can use the Association Rules produced by ODM.

Friday, November 23, 2012

UKOUG 2012-What is it all about

The annual showcase conference of the UKOUG is coming up soon, actually it is just a week away now.

I attended my first UKOUG conference back in 1998 and I’ve been attending it on and off every since. Over the past few years I’ve been very luck to be able to attend it every year and during most of those I’ve presented at too.

This year will be no different as I will be co-presenting with Antony Heljula on using Oracle Data Miner and OBIEE to get some insight of on your data.

The core part of the conference runs over 3 days Monday to Wednesday, with many, many streams of excellent content for each area that the user group covers.  The real problem I have when I attend this conferences is that my interests typically span two if not three of the streams, so I’m typically seen running between presentation.

This year there are two pre-conference events. The first of these is the Oaktable Sunday, where there are two streams of presentations from members of the OakTable networks, who are a bunch of hardcore DBA types. So if you are one of those or would like to be one of those then try to get along to those session on the Sunday.

Also on the Sunday there is a Middleware event. This is being organised by Simon Haslam and Jacco Landlust. Like the OakTable event you will find some hardcode middleware experts sharing some of the work, their discoveries and offering lots of useful advice.

During the main conference look out for the Un-conference sessions where you will have the opportunity to give a short 10 minute plus, no powerpoint talk and some topic or issues you want to discuss. Whether you want to lead a discussion or to just sit in on one then these are a not to be missed. Check out the schedule near the exhibition hall.

The Oracle User Experience team will be at the conference this year to talk to you about your experiences of using the products. In addition they will be setting up a UX lab to get some feedback on their designs.

There will be more talks by members of the OakTable network during the lunch times. These will be shorter than the Sunday talks and again there will be no powerpoint.

You will have the opportunity to get hands-on experience building an Oracle RAC database using virtual machines on your own laptop with help from the experts from the IOUG RAC SIG and Pythian.

In addition to all of this there will be roundtable discussions, master classes and hands on labs.

You may have noticed that I haven’t talked about the actual streams that are running over the 3 days of the conference. There is so much going on at this conference that you will learn so much your boss will be sending you back next year. This conference is the most cost effective training you will ever receive.

I better get packing for a busy few days of learning, networking and having fun at the same time.

I’m going to make another blog post on what what my plans are for the conference, what presentations I will be going to, what events, etc.

Oh and don’t forget my advice in the latest Oracle Scene online or have a read of your free copy if you are attending the conference.

Oh I forgot to mention the social event.  Tut Tut.  There are lots of social and network events too so when you are finished with the presentations for a day, you can enjoy a free drink.

Association Rules in ODM–Part 1

This is a the first part of a four part blog post on building and using Association Rules in Oracle Data Miner. The following outlines the contents of each post in the series on Association Rules

  1. This first part will focus on how to building an Association Rule model
  2. The second post will be on examining the Association Rules produced by ODM – This blog post
  3. The third post will focus on using the Association Rules on your data.
  4. The final post will look at how you can do some of the above steps using the ODM SQL and PL/SQL functions.

image

The data set we will be using for Association Rule Analysis will be the sample data that comes with the SH schema in the database. Access to this schema and it’s data was setup when we created our data mining schema and ODM Repository.

Step 1 – Getting setup

As with all data mining projects you will need a workspace that will contain your workflows. Based on my previous ODM blog posts you will have already created a Project and some workflows. You can either reuse an existing workflow you have used for one of the other ODM modeling algorithms or you can create a new Workflow called Association Rules.

Step 2 – Define your Data Set

Assuming that your database has been setup to have the Sample schemas and their corresponding data, we will be using the data that is in the SH schema. In a previous post, I gave some instructions on setting up your database to use ODM and part of that involved a step to give your ODM schema access to the sample schema data.

We will start off by creating a Data Source Node. Click on the Data Source Node under the Component Palette. Then move your mouse to your your workspace area and click. A Data Source Node will be created and a window will open. Scroll down the list of Available Tables until you find the SH.SALES table. Click on this table and then click on the Next button. We want to include all the data so we can now click the Finish Button.

image

Our Data Source Node will now be renamed to SALES.

Step 3 – Setup the Association Build Node

Under the Model section of the Component Palette select Association. Move the mouse to your work area (and perhaps just the to right of the SALES node) click. Our Association Node will be created.

image

For the next step we need to join the our data source (SALES) with the Association Build Node. Right click on the SALES data node and select Connect from the drop down menu. Then move the mouse to the Association Build node and click. You should now have the two nodes connected.

We will now get the Edit Association Build Node property window opening for us. We will need to enter the following information:

  • Transaction ID: This is the attribute(s) that can be used to uniquely identify each transaction. In our example the Customer ID and the Time ID of the transaction allows us to identify what we want to analyse by i.e. the basket. This will group all the related transactions together
  • Item ID: What is the attribute of the thing you want to analyse. In our case we want to analyse the Products purchased, so select PROD_ID in this case
  • Value: This is an identifier used to specify another column with the transaction data to combine with the Item ID. <Existence> means that you want to see if there are any type of common bundling among all values of the selected Item ID. Use this.

image

Like all data mining products, Oracle has just one Algorithm to use for Association Rule Analysis, the Apriori Algorithm.

Click the OK button. You are now ready to run the Association Build Node. Right click on the node and select Run from the menu. After a short time everything should finish and we will have the little green tick makes on each of the nodes.

image

 

Check out the next post in the series (Part 2) where we will look at how you can examine the rules produced by our model in ODM.

Monday, November 19, 2012

Review Oracle Magazine- July/August 1998

The headline articles for the July/August1998 edition of Oracle Magazine were on designing, developing and delivering Data Marts using the Oracle Database and related tools. The main article looks at the different phases of developing a data mart in 90 days.

One of the key messages in these articles is to keep focused on the business problem and that the technology part is very minor in this. This message is still vey key to the analytics and big data world, keep focused on the business problem.

image

Other articles included:

  • Oracle ships JDeveloper Suite. It included App Builder for Java, Oracle Application Server 4.0, Oracle 8 Database Server, Symantec’s Visual Page HTML editor, and a one year developer’s membership in the Oracle Technology Network. Yes there used to be a cost to be a member of OTN!!!.
  • Oracle We Developer Suite wins the PC Magazine Editor Choice award. The suite comes with full development licences for Designer/2000 Release 2.1, including object extensions, Developer/2000 Release 2.1, Oracle App Builder for Java, Oracle Application Server 3.0, Oracle Database Server (releases 7 and 8) and the Oracle Web Development Kit
  • Oracle Support announce plans to give read only access, via the web, to its Bug database.
  • There was an advert for TOAD when it was still freeware and provided by ToadSoft.
  • Security management for Oracle 8, has been increasing in importance over the past few years. For all those people who have some security responsibilities, here are some key elements for database security: System security, Data security, User security, Password management and System auditing. Security is more than just providing a Firewall.
  • Building Message-based apps with Oracle 8’s Advanced Queuing, involves 5 main steps, including:
    • Start the server’s AQ background process
    • Create a database user account to manage queues
    • Create a user-defined type for application messages
    • Create a queue table and a corresponding queue of the user defined message type
    • Build the application to enqueue and dequeue messages of the user defined message type
  • For the DBAs there was an article on Fast Full Index Scan, how to enable it and gives a number of examples of the hints including the index_fss.

To view the cover page and the table of contents click on the image at the top of this post or click here.

My Oracle Magazine Collection can be found here. You will find links to my blog posts on previous editions and a PDF for the very first Oracle Magazine from June 1987.

Friday, November 16, 2012

Accepted for BIWA Summit–9th to 10th January

I received an email today to say that I had a presentation accepted for the BIWA Summit. This conference will be in the Sofitel Hotel beside the Oracle HQ in Redwood City.

The title of the presentation is “The Oracle Data Scientist” and the abstract is

Over the past 18 months we have seen a significant increase in the demand for Data Scientists. But how does someone become a data scientist. If we examine the requirements and job descriptions of this role we can see that being able to understand and process data are fundamental skills. So an Oracle developer is ideally suited to being a Data Scientist. The presentation will show how an  Oracle developer can evolve into a data scientist through a number of stages, including BI developer, OBIEE developer, statistical analysis, data miner and data scientist. The tasks and tools will be discussed and explored through each of these roles. The second half of the presentation will focus on the data mining functionality available in SQL and PL/SQL. This will consist of a demonstration of an Analytics Development environment and how you can migrate (and use) your models in a Production environment

For some reason Simon Cowell of XFactor fame kept on popping into my head and it now looks like he will be making an appearance in the presentation too. You will have to wait until the conference to find out what Simon Cowell and Being an Oracle Data Scientist have in common.

Check out the BIWA Summit website for more details and to register for the event.

I’ll see you there Smile

Friday, November 9, 2012

Update on : Adding numbers between

Over the past few days I’ve had a number of emails and comments based on my previous post.  My previous post was called ‘Adding numbers between two values’. I included some PL/SQL code that can be used to add up the numbers between two values. I mentioned that this was a question that my pre-teen son (a few year pre-teen) had asked me.

There are two main solutions to the same problem. One involves just using a SELECT and the other involves using recursion. I will come back the these alternative solutions below.

But let me start off with a bit more detail and background to why I approached the problem the way that I did. The main reason is that my son is a pre-teen. Over the past couple of years he as expressed an interest in what his daddy does. We even have matching ORACLENERD t-shirts Smile

When I was working through the problem with my son I wanted to show him how to take a problem and by breaking it down into its different parts we can work out an overall solution. We can then take each of these parts and translate them into code. In this case some PL/SQL, yes it is a bit nerdy and we do have the t-shirt. The code that I gave illustrates many different parts of the language and hopefully he will use some of these features as we continue on our learning experience.

It is good sometimes to break a problem down into smaller parts. That way we can understand it better, what works and what does not work, if something does not work then we will know what bit and also leads to easier maintenance. At a later point as you develop an in-depth knowledge of certain features of a language you can then rewrite what you have to be more efficient.

All part of the learning experience.

Ok lets take a look at the other ways to answer this problem. The first approach is to just use a single SELECT statement.

SELECT sum(rownum + &&Start_Number - 1)
FROM    dual
CONNECT by level <= &End_Number - &&Start_Number + 1;

An even simpler way is

SELECT sum(level)
FROM    dual
CONNECT BY level between &Start_Number and &End_Number;

These queries create a hierarchical query that produce all the numbers between the Start_Number parameter and the End_Number parameter. The SUM is needed to all all the numbers/rows produced.  This is nice and simple (but not that easy for by son at this point).

Thank you to everyone who contacted me about this. I really appreciated your feedback and please keep your comments coming for all my posts.

Tuesday, November 6, 2012

Adding numbers between two values

My son asked me the other day, what is the total number if you add all the numbers between Zero and 100.
We could have sat down to work it out with some paper and a pen, but instead I decided to introduce him to the world of Oracle, SQL and PL/SQL
The first step we took was to work out how you would do it on paper for some of the numbers. Then we translated this into some PL/SQL code. OK I did a lot this but he did seem to understand and follow what I was doing.
So the following Function is what we ended up with to add all the numbers between two numbers and return the answer.
CREATE or REPLACE function AddNumsBetween
       ( pStartNum IN NUMBER,
         pEndNum IN NUMBER)
   RETURN NUMBER
IS
   vSum   Number := 0;
BEGIN
   FOR i IN pStartNum .. pEndNum LOOP
      vSum := vSum + i;
   END LOOP;
   return vSum;
END;
/

The next step was to write some code to call this function. The code prompts the user to enter the Start number and End number.
set serveroutput on
DECLARE
   vStartNum  NUMBER := 0;
   vEndNum   NUMBER := 100;
   vAnswer    NUMBER := 0;
BEGIN
   vStartNum := &Start_Number;
   vEndNum := &End_Number;
   vAnswer := AddNumsBetween(vStartNum, vEndNum);
   dbms_output.put_line('The sum of numbers between '||vStartNum||' and '||vEndNum||' is '||vAnswer||'.');
END;
/

To answer by son’s original query, we used Zero and 100 as our inputs.
image
The answer to the question is 5,050.

Sunday, November 4, 2012

Events for Oracle Users in Ireland-November 2012

November (2012) is going to be a busy month for Oracle users in Ireland. There is a mixture of Oracle User Group events, with Oracle Day and the OTN Developer Days. To round off the year we have the UKOUG Conference during the first week in December.

Here are the dates and web links for each event.

Oracle User Group

The BI & EPM SIG will be having their next meeting on the Tuesday 20th November. This is almost a full day event, with presentations from End Users, Partners and Oracle product management. The main focus of the day will be on EPM, but will also be of interest to BI people.

As with all SIG meetings, this SIG will be held in the Oracle office in East Point (Block H). Things kick off at 9am and are due to finish around 4pm with plenty of tea/coffee and a free lunch too.

image

Remember to follow OUG Ireland on twitter using  #oug_ire

Oracle Day

Oracle will be having their Oracle Day 2012, on Thursday 15th, in Croke Park. Here is some of the blurb about the event,  “…to learn how Oracle simplifies IT, whether it’s by engineering hardware and software to work together or making new technologies work for the modern enterprise. Sessions and keynotes feature an elite roster of Oracle solutions experts, partners and business associates, as well as fascinating user case studies and live demos.

This is a full day event from 9am to 5pm with 3 parallel streams focusing on Big Data, Enterprise Applications and the Cloud.

Click here to register for this event.

Click here for the full details and agenda.

OTN Developer Days

Oracle run their developer days about 3 times a year in Dublin. These events are run like a Hands-on Lab. So most of the work during the day is by yourself. You are provided with a workbook, a laptop and a virtual machine configured for the hands-on lab. This November we have the following developers days in the Oracle office in East Point, Dublin.

Tuesday 27th November (9:45-15:00) : Real Application Testing

Wednesday 28th November (9:00-14:00) : Partitioning/Advanced Compression

Thursday 29th November (9:15-13:30) : Database Security

Friday 30th November (9:45-16:00) : Business Process Management Using BPM Suite 11g

As you can see we have almost a full week of FREE training from Oracle. So there is no reason not to sign up for these days.

UKOUG Conference – in Birmingham

In December we have the annual UKOUG Conference. This is the largest Oracle User Group conference in Europe and the largest outside of the USA. At this conference you will have some of the main speakers and presentations from Oracle Open World, along with a range of speakers from all over the work.

In keeping with previous years there will be the OakTable Sunday and new this year there will be a Middleware Sunday. You need to register separately for these events. Here are the links

OakTable Sunday

Middleware Sunday

The main conference kicks off on the Monday morning with a very full agenda for Monday, Tuesday and Wednesday. There are a number of social events on the Monday and Tuesday, so come well rested.

On the Monday evening there is the focus pubs. This year it seems to have an Irish Pub theme. At the focus pub event there will be table for each of the user group SIGs. 

Come and join me at the Ireland table on the Monday evening.

The full agenda in now live and you can get all the details here.

I will be giving a presentation on the Tuesday afternoon titled Getting Real Business Value from Predictive Analytics (OBIEE and Oracle Data Mining). This is a joint presentation with Antony Heljula of Peak Indicators.

Friday, November 2, 2012

OOW content/slides are still available

For those people who where lucky to get the Oracle Open World (OOW) and for all the many thousands of people who were not able to make it to OOW, the slides from almost all the presentations are still available.

To get your hands on these presentation slides, all you need to do is to go to the Oracle Open World website

http://www.oracle.com/openworld/index.html

Click on the Tools option on the menu and then click on Schedule Builder. You will need your Oracle Single-Sign-On username and password. Once entered you should get conference content and Schedule page.

image

You can search the content catalog for the presentations you are interested in and download the presentations.

There was been some mutterings that the presentation slides and access to the schedule build will be restricted at some time in the near future.

So get the conference material now.

While you are on the Oracle Open World site, why not sign up for notifications for the 2013 conference. They will probably start around early March.

Thursday, November 1, 2012

ASCII to character conversion in Oracle

Here is code code that will produce formatted output of the characters and their ascii values. The formatting is broken into lower case letters, uppercase letters, characters with an ascii value less than an ‘a’ and characters whose ascii characters are greater than a ‘z.

Code

set serveroutput on FORMAT WRAPPED
DECLARE
    vTab           VARCHAR2(5) := CHR(9);
    vNum          NUMBER := 0;
    vString       VARCHAR2(80) := '';
BEGIN  
   --
   -- Formatted lower case letter to ASCII values
   --
   dbms_output.put_line('Formatted Lower Case Letters to ASCII values');
   dbms_output.put_line('-------------------------------------------------------');
   FOR i IN ASCII('a') .. ASCII('z') LOOP
      IF vNum < 6 THEN
         vString := vString||CHR(i)||' : '||i||vTab;
         vNum := vNum + 1;
      ELSIF vNum = 6 then
         dbms_output.put_line(vString||CHR(i)||' : '||i);
         vNum := 0;
         vString := '';
      ELSE
         dbms_output.put_line('ERROR');
      END IF;
   END LOOP;
   dbms_output.put_line(vString);

   --
   -- Formatted upper case letter to ASCII values
   --
   vString := '';
   vNum := 0;

   dbms_output.new_line;
   dbms_output.new_line;
   dbms_output.put_line('Formatted Upper Case Letters to ASCII values');
   dbms_output.put_line('-------------------------------------------------------');
   FOR i IN ASCII('A') .. ASCII('Z') LOOP
      IF vNum < 6 THEN
         vString := vString||CHR(i)||' : '||i||vTab;
         vNum := vNum + 1;
      ELSIF vNum = 6 then
         dbms_output.put_line(vString||CHR(i)||' : '||i);
         vNum := 0;
         vString := '';
      ELSE
         dbms_output.put_line('ERROR');
      END IF;
   END LOOP;
   dbms_output.put_line(vString);

   --
   -- Formatted chars less than 'a' to ASCII values
   --
   vString := '';
   vNum := 0;

   dbms_output.new_line;
   dbms_output.new_line;
   dbms_output.put_line('Formatted Letters, less than a  to ASCII values');
   dbms_output.put_line('-------------------------------------------------------');
   FOR i in 0 .. ASCII('a')-1 LOOP
      IF vNum < 6 THEN
         vString := vString||CHR(i)||' : '||i||vTab;
         vNum := vNum + 1;
      ELSIF vNum = 6 then
         dbms_output.put_line(vString||CHR(i)||' : '||i);
         vNum := 0;
         vString := '';
      ELSE
         dbms_output.put_line('ERROR');
      END IF;
   END LOOP;
   dbms_output.put_line(vString);

   --
   -- Formatted chars greater than 'Z' to ASCII values
   --
   vNum := 0;
   vString := '';

   dbms_output.new_line;
   dbms_output.new_line;
   dbms_output.put_line('Formatted Letters, greater than z  to ASCII values');
   dbms_output.put_line('-------------------------------------------------------');
   FOR i IN ASCII('z') .. ASCII('z')+133 LOOP
      IF vNum < 6 THEN
         vString := vString||CHR(i)||' : '||i||vTab;
         vNum := vNum + 1;
      ELSIF vNum = 6 then
         dbms_output.put_line(vString||CHR(i)||' : '||i);
         vNum := 0;
         vString := '';
      ELSE
         dbms_output.put_line('ERROR');
      END IF;
   END LOOP;
   dbms_output.put_line(vString);

END;
/

Output

Formatted Lower Case Letters to ASCII values
-------------------------------------------------------
a : 97  b : 98  c : 99  d : 100 e : 101 f : 102 g : 103
h : 104 i : 105 j : 106 k : 107 l : 108 m : 109 n : 110
o : 111 p : 112 q : 113 r : 114 s : 115 t : 116 u : 117
v : 118 w : 119 x : 120 y : 121 z : 122


Formatted Upper Case Letters to ASCII values
-------------------------------------------------------
A : 65  B : 66  C : 67  D : 68  E : 69  F : 70  G : 71
H : 72  I : 73  J : 74  K : 75  L : 76  M : 77  N : 78
O : 79  P : 80  Q : 81  R : 82  S : 83  T : 84  U : 85
V : 86  W : 87  X : 88  Y : 89  Z : 90


Formatted Letters, less than a  to ASCII values
-------------------------------------------------------
  : 0   ☺ : 1   ☻ : 2   ♥ : 3   ♦ : 4   ♣ : 5   ♠ : 6
: 7 : 8                 : 9
: 13   ♂ : 11  ♀ : 12
♫ : 14  ☼ : 15  ► : 16  ◄ : 17  ↕ : 18  ‼ : 19  ¶ : 20
§ : 21  ▬ : 22  ↨ : 23  ↑ : 24  ↓ : 25  → : 26  ← : 27
∟ : 28  ↔ : 29  ▲ : 30  ▼ : 31    : 32  ! : 33  " : 34
# : 35  $ : 36  % : 37  & : 38  ' : 39  ( : 40  ) : 41
* : 42  + : 43  , : 44  - : 45  . : 46  / : 47  0 : 48
1 : 49  2 : 50  3 : 51  4 : 52  5 : 53  6 : 54  7 : 55
8 : 56  9 : 57  : : 58  ; : 59  < : 60  = : 61  > : 62
? : 63  @ : 64  A : 65  B : 66  C : 67  D : 68  E : 69
F : 70  G : 71  H : 72  I : 73  J : 74  K : 75  L : 76
M : 77  N : 78  O : 79  P : 80  Q : 81  R : 82  S : 83
T : 84  U : 85  V : 86  W : 87  X : 88  Y : 89  Z : 90
[ : 91  \ : 92  ] : 93  ^ : 94  _ : 95  ` : 96


Formatted Letters, greater than z  to ASCII values
-------------------------------------------------------
z : 122 { : 123 | : 124 } : 125 ~ : 126 ⌂ : 127 Ç : 128
ü : 129 é : 130 â : 131 ä : 132 à : 133 å : 134 ç : 135
ê : 136 ë : 137 è : 138 ï : 139 î : 140 ì : 141 Ä : 142
Å : 143 É : 144 æ : 145 Æ : 146 ô : 147 ö : 148 ò : 149
û : 150 ù : 151 ÿ : 152 Ö : 153 Ü : 154 ø : 155 £ : 156
Ø : 157 × : 158 ƒ : 159 á : 160 í : 161 ó : 162 ú : 163
ñ : 164 Ñ : 165 ª : 166 º : 167 ¿ : 168 ® : 169 ¬ : 170
½ : 171 ¼ : 172 ¡ : 173 « : 174 » : 175 ░ : 176 ▒ : 177
▓ : 178 │ : 179 ┤ : 180 Á : 181 Â : 182 À : 183 © : 184
╣ : 185 ║ : 186 ╗ : 187 ╝ : 188 ¢ : 189 ¥ : 190 ┐ : 191
└ : 192 ┴ : 193 ┬ : 194 ├ : 195 ─ : 196 ┼ : 197 ã : 198
à : 199 ╚ : 200 ╔ : 201 ╩ : 202 ╦ : 203 ╠ : 204 ═ : 205
╬ : 206 ¤ : 207 ð : 208 Ð : 209 Ê : 210 Ë : 211 È : 212
ı : 213 Í : 214 Î : 215 Ï : 216 ┘ : 217 ┌ : 218 █ : 219
▄ : 220 ¦ : 221 Ì : 222 ▀ : 223 Ó : 224 ß : 225 Ô : 226
Ò : 227 õ : 228 Õ : 229 µ : 230 þ : 231 Þ : 232 Ú : 233
Û : 234 Ù : 235 ý : 236 Ý : 237 ¯ : 238 ´ : 239 ­ : 240
± : 241 ‗ : 242 ¾ : 243 ¶ : 244 § : 245 ÷ : 246 ¸ : 247
° : 248 ¨ : 249 · : 250 ¹ : 251 ³ : 252 ² : 253 ■ : 254
  : 255

PL/SQL procedure successfully completed.

Observations

There are two things that stand out in this. The first is there is sound produced. This is because one of the characters is defined this way. It is ASCII number 7. This can be repeated using the following:

select chr(7) from dual.

The second is the formatting of the lines for ascii codes 8 to 12. We can see that one of the ascii codes does not get displayed and the ordering of this is not as expected. This is due to ascii 10 being a line feed.