Introduction to Oracle Database 12c

With the launch of DB 12c in 2013, Oracle introduced a new architectural concept, called “multitenant databases”, where you have one super database (=container; CDB) and one or more sub databases (= pluggable DBs; PDB).

Before running the installer on an Oracle Linux 6 environment, a library can be installed through yum to meet all the system per-requisites:

yum install oracle-rdbms-server-12cR1-preinstall

The software installer and DBCA are similar to 11g, except for this screen where you can pre-configure your CDB and PDBs:

db12c01

This DBCA execution will not only create a CDB and 1 PDB, but a “seed pluggable database” as well.  You can use this seed database as a template to create other pluggable databases.

db12c02

By default, after running the DBCA, all CDBs and PDBs are up and running.

Now, we will reboot the host machine and try to start all of our components.

Is there a difference when starting the listener and the CDB?

No!  You can start the listener and your CDB in exactly the same way as you did with your pre-12c database.

How can you connect to the CDB?

Very simple: just the same as in the past with pre-12c databases.

$ sqlplus system@apexdev

SQL*Plus: Release 12.1.0.1.0 Production on Thu Mar 19 22:53:55 2015

Copyright (c) 1982, 2013, Oracle.  All rights reserved.

Enter password:

Last Successful login time: Mon Mar 16 2015 22:20:50 +01:00

Connected to:

Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 – 64bit Production

With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options

SQL>

Are the PDBs opened by default, when starting the CDB?

No.  This can be verified by this query:

SQL> select open_mode from v$pdbs where name=’APEXDEV_PDB1′;

OPEN_MODE
———-
MOUNTED

The PDB is mounted; to open it, just run this command:

SQL> alter pluggable database apexdev_pdb1 open read write;

Pluggable database altered.

SQL> select open_mode from v$pdbs where name=’APEXDEV_PDB1′;

OPEN_MODE
———-
READ WRITE

Note: this must be done as “SYSDBA”.

How can we connect to the PDB?

There are 2 methods:

First method: connect to the CDB and then switch to the PDB by setting the container:

$ sqlplus system@apexdev

SQL> show con_name

CON_NAME
——————————
CDB$ROOT
SQL> alter session set container=apexdev_pdb1;

Session altered.

SQL> show con_name

CON_NAME
——————————
APEXDEV_PDB1

Second method: Modify your tnsnames.ora file by adding an entry for the PDB, based on the CDB entry.

Now, you can connect as usual to the PDB:

[oracle@ol6db1 oracle]$ sqlplus system@apexdev_pdb1

SQL*Plus: Release 12.1.0.1.0 Production on Tue Mar 24 20:37:38 2015

Copyright (c) 1982, 2013, Oracle. All rights reserved.

Enter password:
Last Successful login time: Thu Mar 19 2015 18:59:51 +01:00

Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 – 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options

SQL> show con_name

CON_NAME
——————————
APEXDEV_PDB1

As you can see, it is all quite easy.  One of the main benefits of this architecture is that you can handle every PDB as a separate database that can be upgraded or plugged/unplugged independently from other databases.

And of course your database will be ready for the cloud!

5 Minute JavaScript #17: some and every

In the previous blogpost we discussed the map method on arrays in JavaScript. We still have some useful methods the go. Next in line are the some and every methods. These methods are similar and can be very useful when validating data.

var isEven = function (n) { return n % 2 === 0 };
var areAllEven = [2, 4, 6].every(isEven);
var someEven = [1, 2, 3].some(isEven);

The every method will check if for every element in the list, the callback functions returns true. If there is one single item in the array that returns false, the every method will return false as well. The some method is satisfied when there is at least one element in the array where the callback returns true.

var stockItem = { hasBeenShipped: true };
var selection = [/* list of stock items selected in a list */];
var hasNotBeenShipped = function (si) { return !si.hasBeenShipped };
var hasBeenShipped = function (si) { return si.hasBeenShipped };

$('#sendStockItems').attr('disabled', selection.every(hasNotBeenShipped));
$('#sendStockItems').attr('disabled', selection.some(hasBeenShipped));

The example here will disable a button when the selection in the list contains one or more items that already have been shipped. This code is very readable and concise. You can almost read exactly what it does: set attribute disabled when selection has some items that hasBeenShipped.

5 Minute JavaScript #16: map

Last week we took a look at the filter functionality. This week I will show you one of my favourite array methods called: “map”. It’s extremely powerful and useful in so many ways. The purpose of map is simple, it transforms an item in an array and pushes that transformation into a new array. The method then returns that newly created array with all the transformed items. A simple example will show you what it does.

var square = function (item) { return item * item; };
var squares = [1, 2, 3, 4].map(square);

In this example we just square a number in the array. The result will be a new array but with the squared items.

This example is easy to understand, but you might wonder what the practical use is for this function. Well in a lot of applications I find myself using map to select the identifier from an object and pass along a map of id’s.

var user = { id: 'UUID', version: 0, name: 'User 1' };
var users = [/* a list of users */];
var ids = users.map(function (u) {return u.id;}); 
var versions = users.map(function (u) {return u.version});
var idsAndVersions = users.map(function (u) { 
    return { 
        id: u.id, 
        version: u.version 
    };
});

These lists can be used in frameworks, api’s, ajax requests, caching, etc… everywhere you don’t need to know / send the full information of the user.

5 Things I wish I knew about APEX when I just started (part 3)

In my previous post of this series, I talked about cookie sharing in APEX. The next post in this series is about build options, I hope you enjoy it.

Build Options

Imagine having to release an apex application, but you don’t want some parts released in to the production environment yet, because they are unfinished, or not tested. Or you want to disable a module in your application for some reason.

Apex provides a solution for this called build options.

You can find the build options under shared components > logic > build options

Let’s create 2 build options:

The first one will keep the component active in our development environment, but will disable it on export so the developed content is disabled in our production environment.

buildoptions1

The second one will disable content in the application, and take over this behavior on export to our production environment.

buildoptions2

For the status there are two options possible:

Exclude, will disable the content in the current application, and include will keep it enabled in the current application.

For the default on export there are 3 possible combinations:

Same as current will take over whatever has been chosen in status when exporting a page. Exclude will disable the components on export of the application. Include will enable the components on export of the application.

Build options can be attached to any component in apex: pages, processes, regions, items, and can be found under the configuration tab when editing the components.

buildoptions3

As a test you can put the 2 build options on some page items in your current application.

When you run the page you will notice that in your development environment, one item will be visible and one will be gone from the page.

When you take an export and import it back in the new environment you will notice both items are removed from the page.

That’s it! The fourth blog in this series will be about recovering applications and page elements using flashback, and will be online soon.

5 Minute JavaScript #15: filter

In the previous blogpost we discussed the forEach method that iterates over every array. We can now create a filtered array by using this function.

var filtered = []
arr.forEach(function (item) { if (item.isOkay) filtered.push(item); });

While this will work fine, we still need to predefine our filtered array and push it in this array ourselves. We don’t need to… we could just use the filter method on the array prototype.

var filtered = arr.filter(function (item) { return item.isOkay; });

This code isn’t only more readable and a little shorter, it also allows you to chain these methods. Also, you can use abstract validation functions to reuse the filtering.

var isEven = function (number) { return number % 2 === 0; };
var filtered = [1, 2, 3].filter(isEven);

A more practical example:

var stockItem = { category: "toys" /*, and other properties */ };
var stockItems = [/* has a bunch of stockitems with different categories */];

var product = { category: "toys", stockItems: [] };
var products = [/* has a bunch of products */];

var belongsToToyCategory = function (item) { return item.category === "toys";  };

var filteredStockItems = stockItems.filter(belongsToToyCategory);
var filteredProducts = products.filter(belongsToToyCategory);

5 Minute JavaScript #14: forEach

After discussing how to create a range in the last post, we will discuss some of the array methods and how to use them to make your code more readable and concise.

First of all, I want to add that every array method uses the callback pattern. We’ll do a post on this pattern later, when discussing Asynchronous JavaScript, but for now you need to know that callbacks in these functions are called for every item in the array.

The easiest array method is called forEach and will just iterate over every item in the array.

	[1, 2, 3].forEach(function (item) { console.log(item); });

Most people will recognize this method. It iterates over every item and does nothing with the return value you provide. What most programmers don’t know is that you have some additional features in forEach.

	[1, 2, 3].forEach(function (item, index, array) { this.log(item);  }, console);

The forEach function lets you set the functions context (= this, more later) as well. In the previous example I injected console as the ‘this’ value in callback function.

But beware:

	function hasNumber (arr, number) {
		arr.forEach(function (item) { 
			if (item === number) return true; 
		});
	}

While this code might look okay, you must know that JavaScript’s forEach is still a callback function. Returning the value true inside the callback won’t result in the global function (hasNumber) to return true. You should refactor this code to

	function hasNumber (arr, number) {
		var found = false;
		arr.forEach(function (item){ if (item === number) found = true; });
		return found;
	}

By using the some-method you will get an even easier result, but more about that in a future post.

OGh APEX World 2015

DSC_9284-001 (800x533)

iAdvise Diamond Sponser APEX World 2015

After 5 successful earlier editions of the APEX World day, they chose a different venue for the 2015 edition. The ship SS Rotterdam was the setting for the annual APEX World event. For us, it was not only the location that was special, we were also official Diamond Sponsor of APEX World 2015! And a great day it was! Not only to meet a lot of nice people from the Benelux APEX community, but also for the great sessions that have provided us with a lot of inspiration for the upcoming period. It was really an honour for us to be the Diamond Sponsor this year.

 

Like previous years, the day started with a short opening. This year, Reinier van Grieken, vice president and managing director of Oracle Netherlands was invited to do the opening. He emphasized that the OGh did a great job by welcoming such an enormous audience, which continued to grow over the past 5 years (more than 400 visitors this year).

In this overview we will take you aboard the SS Rotterdam on the 25th of March, so if you missed it, you’ll still get the highlights. And if you were there, you can look back on a great day.

 

Keynote: OraEvents – Stijn van Raes (iAdvise) & Yves van Looy (Oracle Belgium)

Stijn van Raes at APEX World 2015

Stijn van Raes at APEX World 2015

In an entertaining presentation the speakers told us about how Oracle and iAdvise created the situation of a supplier – customer – supplier – customer. iAdvise was hired to build the OraEvents application for Oracle (www.oraevents.eu). The architecture of this application makes it possible to collect data about the interests of registered users. In some situations this can be a huge advantage. For example, there was a situation when Oracle organized an event but it was really hard to get enough attendees. Oracle Belgium searched in the database of OraEvents and in half an hour they filled up the event.

At the end of this keynote, iAdvise wondered what could be possible features in future APEX versions (like  APEX 6, APEX 7 or even later). Thoughts about single page web applications, Node.js integration and Source Control were brought to attention. iAdvise hopes that the APEX community will think about these possible features and bring over these ideas on  https://apex.oracle.com/vote or the newly formed linkedin group http://goo.gl/L9DirJ

 

APEX suitable for high volume environments – PostNL & Fiton

Fiton and PostNL developed an application to process postal orders in a very easy and quick manner. Not only national but also international orders can be handled with this system.

Basic and simple APEX functionality was used to enter barcodes in a system which looked like some kind of wizard. Only 4 APEX pages were developed, besides a login system. The application was based on Theme 13 in APEX. The part of the system that takes care of printing invoices was built as a Java applet. The philosophy of this client case was: “Less is more”. Keep your application as simple as possible.

 

Oracle Forms to Oracle Application Express migration – iAdvise (Yvonne van Dorst) and Robeco (William de Vries)

Robeco decided to migrate 7 applications which had been developed with Oracle Designer. These applications have to be compatible with at least an Oracle 11g database and will need to have a distinct corporate identity. APEX turned out to be the best tool. In the beginning Robeco and iAdvise started to migrate 3 applications with the intention of migrating 4 more applications in the future. For Robeco it was very important to use one template for all applications. This could be realized by an APEX theme developed by iAdvise based on bootstrap in combination with a JavaScript framework.
All 7 APEX applications were developed in a period of 3 months. The business has become APEX minded and almost all questions are more or less like: “Can we do this in APEX?” The answer in most cases is: “Yes we can!” Robeco is a very satisfied APEX customer.

 

Design of good-looking, flexible and responsive applications – iAdvise (Menno Hoogendijk) and Twinq (Laurens Hamelink)

Twinq develops software for co-operations of owners of apartments. People who use this software will do this on several devices like a desktop (24 inch), a tablet (10 inch) or smartphone (5 inch). Twinq’s vision is that software has to be sexy and good-looking. To make this kind of software for all types of devices, iAdvise and Twinq used bootstrap. The APEX application uses AJAX and javascript, but all in favor of usability. Besides this, the applications are equipped with the possibility to use keyboard shortcuts.

At the end of this presentation, the audience was asked to visit an online vote, just like tinder. They could indicate whether they really experienced the demo as “Sexy Software” or not. More than 80% was convinced of the sexiness of the software.

 

Hidden Nuggets in Application Express 5.0 Page Designer – David Peake (Oracle US)

Everyone knows that APEX 5.0 has a lot in store for us. In this presentation, David Peake took
us through the new page designer and told us his favorite features.

The page designer is now divided in three sections. The old tree view can be consulted on the left side of the screen.

The middle section consists of a wide grid layout where we can easily drag and drop new items to our page. Messages will show you what is missing for the new created items.

In the right section we can directly see and edit the properties of the selected item. This new interface allows us to develop much more efficiently. Besides editing one item at a time, it is now possible to edit multiple items. This will save us a lot of time, for example when you want to change the template of all your labels. And when the latest adjustment to your page does not meet your expectations, you can now undo and redo it by simply pressing a button.

Not only the grid layout is quite convenient, keyboard shortcuts will soon be our best developing buddies. To help us along the way, help texts and search capabilities have been increased considerably. Now we will lose less time, if we are looking for that one particular item.

The page designer will give us the possibility to develop even faster!

 

Interactive Reports: Watch out for the Pitfalls! – Peter Raganitsch (FOEX (AT))

In APEX, we’ve got two different report types to work with: Classic and interactive reports. Many developers prefer the interactive report, because the user can change the appearance of the data through several manipulations. This means that the query behind this report is also adjusted. To figure out how the query will look like after a few filters, you can use the debug function. To get the full query available in logging, you must replace the ‘YES’ with ‘LEVEL9’ in the url. This gives you a more detailed logging. You can also add a small PL/SQL code in the application properties (Security, Database Session, Initialization PL/SQL code):
“APEX_DEBUG.enable (9) ;”. Remember after testing to remove it again.

The pagination type also affects the query of your report. If you use the type ‘X to Y of Z’, then the query will be extended to return the total number of rows. Therefore, use the type ‘X to Y’ for reports with many records.

Also, there is a very useful package for interactive reports named APEX_IR. This can be used to see the full runtime query of your interactive reports, add filters, clear or reset the report settings, delete saved reports and manage subscriptions.

Version 5.0 has several enhancements on interactive reports. Henceforth, it will be possible to use multiple interactive reports per page. Besides that, the action region – after selecting an option in the action menu – will be showed in modal dialogs instead of above the report. The menu is also expanded with the pivot function and the end user can now do a group by on a maximum of eight fields instead of five. With all these improvements, version 5.0 will be very well received by both, developer and end user.

 

A Spotlight on the Smaller Features of APEX 5 – Dietmar Aust (Opal Consulting (DE))

After three early adopters and a pre-production version of APEX 5, everyone nowadays knows about the most important and biggest new features of APEX 5. But what about those features you don’t notice immediately? Dietmar Aust took us through some of those features during his session about the smaller features of APEX 5.

One of the functional improvements Dietmar told us about is: the file storage. In the past apex versions there were no relative file paths, you had to upload your files individually and updating your files took a lot of time. In the new file storage you do have relative file paths and there is the possibility to upload zip files that will be extracted into the correct folders. Updating your files can be done this way too. Also after updating your files you’ll notice at runtime that the version number, which you can find in the url referencing your files has changed to avoid caching issues.

Another runtime engine improvement is the extended substitution syntax where you can now define different escaping modes. For example: if you use a dynamic action that creates a JavaScript alert to show an application item like ‘&P1_ITEM.’. In this case, cross site scripting can be applied. To avoid this there is now the possibility to escape JS syntax by defining the application item like this: ‘&P1_ITEM!JS.’.  There are a few more escaping options that can be used. These can be found in the slides that you can download from Dietmar Aust’s blog (http://daust.blogspot.be/2015/03/slides-from-my-presentation-at-apex.html) like all other improvements that have been discussed in the session.

 

Keynote: Elegance in the Enterprise – Shakeeb Rahman (Oracle US)

On every project I’ll try to surpass my previous creations in usability and design. And every time I’ll spend some time analyzing the most popular websites about their latest user interfaces and the way they interact with the end user. How do they present their navigation? Where do they put the buttons? And how do they organize their content on a page? All these questions are important because you want your users to feel comfortable when they use your application.

This keynote felt like a spring breeze on the – maybe a little bit – too hot SS Rotterdam. It was refreshing to see the amount of dedication, consideration and research the APEX design development team put in their Universal Theme. Shakeeb Rahman brought a lot of liberating facts about the way users interact with web applications to our attention. One of the statements that caught my attention was:

Most users put a higher rate on an application after the design is improved because they believe it works better than the old one.

Shakeeb also told us to think twice before using reports. Because in some cases it may not be the best approach for presenting the data to the end user. Sometimes it’s more efficient to use a diagram or a chart because users instantly see how your data it related. And if using a report still is the best approach, try to eliminate the columns users don’t really need to see right away. Minimizing the amount of data on a screen results in faster reading and, in that way, is more efficient.

Another thing to reflect on when building your application, is to split the contents into smaller bits by grouping similar fields. By dividing your contents, users don’t see your page as a big chunk of data,  but more like smalls pieces of useful information.

The new built-in template that comes with APEX 5 results in easy-to-create, smart, responsive web applications because APEX has done the research for you. It uses built-in crisp icons and follows the currently hot “flat design trend”. Now it’s not only faster to create user friendly web application it’s also much easier because they put all the know-how about user interaction in the new and improved application builder.

That’s also handy because now you can take a peek at how APEX pages are designed if you’re looking for inspiration instead of googling around the web like I used to do before.

iAdvise consultant at APEX World 2015

iAdvise consultant at APEX World 2015