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How to Prepare for the Denodo Platform 6.0 Certified Developer Exam

The Denodo Platform 6.0 Certified Developer (DEN60EDUCD) exam developers’ knowledge of the Denodo Platform and validates if they have the skills required by companies that use Denodo Platform 6.0.

DEN60EDUCD aims to provide organizations that use Denodo Platform 6.0 with a means of identifying suitably qualified staff for designing, developing, and deploying real projects with the Denodo Platform

This exam covers the following technical topics and subject areas:

 

 

The Principles of Data Virtualization

In this section the examinee should demonstrate that they understand the basic concepts of data virtualizacion: 

  • The Current Data Problem
  • Data Virtualization: The Basic Definition 
  • The Principles of Data Virtualization 
  • Data Virtualization Use Cases 

How to prepare

This is a theoretical section that covers the basic definition, principles and use cases of data virtualization. 

To start preparing for this section we recommend that you visit the Denodo Site where you can find helpful content, such as:  A Data Virtualization Overview, How It Works, Benefits and Data Virtualization Solutions

Next step is to start reviewing the Denodo Community tutorial, the introduction includes a definition of the common data problems that organizations face nowadays and how they can be solved using data virtualization. 

All the content related to this section is included in the topic “Data Virtualization. Introduction” which is included in the official Denodo course Data Virtualization Developer Introduction.

 

Denodo Architecture and Components

This section covers the basic concepts and an overview of the Virtual DataPort Administration tool. The examinee should have some knowledge on the following topics:

  • Data Access Layer
    • Wrappers
    • Base Views 
  • Data Integration Layer 
    • Derived Views 
    • How VDP Works When a Query is Received 
  • Data Publishing Layer 
    • How to Access the Created Virtual Schema 
  • Basic Concepts
    • Basic VQL
    • Data Definition
    • Primary Keys
    • Folders
    • Associations
    • Query Execution

How to prepare

This section is mainly theoretical, it is important to have a good understanding of the Virtual DataPort Architecture including the different layers and the basic concepts related to the Virtual Data Port.

The first step you should take is to review the official documentation that explains the General Architecture of the Virtual DataPort. In this section, the physical layer, logical layer and user layer are explained in detail.

The best way to start learning about the basic concepts of the Virtual DataPort is to review the first steps section of the tutorials which is available in the Denodo Community.

This section also includes the basic concepts of primary keys and associations.

These concepts are included under the topics “Virtual DataPort. Architecture” and “Virtual Data Port. Basic Concepts” included in the official Denodo course: Data Virtualization Developer Introduction.

 

The Virtual DataPort Administration Tool

This section covers all the options and menus that are available in the Virtual DataPort Administration Tool.

The main areas that are covered in this section are: 

  • Starting Up the Virtual DataPort Server
  • Virtual DataPort Administration Tool
    • How to Start the Tool
    • Main Areas
    • Folders
    • Available Data Sources
    • Available Operations
    • Publishing Views
    • Quick Search
    • Administration Menu
    • Tools Menu

How to prepare

The best way to prepare for this section is by using the Virtual DataPort Administration tool and trying out different options. Here are the main options of the administration tool and the links to the official documentation: 

In order to launch the the Virtual DataPort server and the admin tool, we recommend that you read the “Installation And Execution” section. 

All the available options of the VDP administration tool are explained in the topic “Virtual DataPort Administration tool” included in the official Denodo course Data Virtualization Developer Introduction.

 

Connecting to Data Sources

This section contains all the information on the possible data sources that you can connect to using the Denodo Platform. It also contains further information on the creation and configuration of base views. 

How to prepare

In order to prepare for this section properly, it is preferable that you have practical experience. You can gain the necessary experience by completing various tutorials available in the Denodo Community. You can start by creating a JDBC data source and base views which is covered in the Connecting to Sources tutorial. 

Next, there is an example in the Virtual DataPort Administration Guide which explains how to create different data sources and base views graphically, starting with JDBC and web services data sources. 

The creation of data sources and base view is very similar, it is simply a case of changing the connection parameters. Once you have understood this process, you can review every data source in more detail in the administration tool or in the Virtual DataPort Administration guide.

As well as the basic way of creating the different data sources, we recommend that you also review the following information related to this section: 

We recommend that you create a data source and a base view of every type to check the necessary configuration and understand what is required for each data source.

Finally, it is important to note that this section contains questions related to the topic of JMS listeners. It’s a good idea to try configuring a JMS listener in the Virtual DataPort Administration tool for yourself to understand how works. 

All these elements are explained in more detail  in the topics “JDBC”, “ODBC”, “Web Services”, “Delimited Files”, “LDAP”, “JSON”, “Excel”, “Custom” and “JMS Listener” in the official courses: Data Virtualization Developer Introduction and Data Virtualization Developer Basics.

 

Writing VQL Queries to Read Data from Data Sources

The Denodo Virtual DataPort uses VQL (Virtual Query Language) for data definition and data manipulation. VQL enables administrators to create and update the elements that constitute the system catalog, as well as enabling them to query and update the unified information views. The examineer should be familiar with VQL. 

Please note: VQL supports two types of sentences: DDL and DML.

  • DDL (Data Definition Language): is used to create and manage views. For example: CREATE, DROP, ALTER, DESC…
  • DML (Data Manipulation Language): is like SELECT, which enables query execution and the definition of derived views. 

Virtual DataPort supports normal queries, but it also contains a set of predefined stored procedures and enables users to import custom developed Java stored procedures.

How to prepare

The examinee should be able to understand the VQL language. The best way to prepare for this section is to create different elements and execute different queries in the VQL Shell of the Virtual DataPort Administration tool. This is a list of all the main parts of the VQL language: 

All the information related to VQL is contained in the guide “Virtual DataPort VQL Guide.” The Advanced Data Virtualization Developer course also contains all the information related to this section under the topic “Virtual DataPort Advanced VQL.”

 

Combining Data Sets

This section contains questions about how to create derived views, which combine data from different sources. 

The following sections describe the process of creating the following types of views using our example to illustrate the process:

  • Selection Views
  • Union Views
  • Join Views
  • Flatten Views
  • Intersect Views
  • Minus Views

How to prepare

The examinee should be able to understand all the available operations in Virtual DataPort and how to configure them. The best way to understand how to create different derived views is create a view of every type. These are all the operations that are contained in this section: 

  • Selection Views
  • Union Views
  • Join Views
  • Flatten Views
  • Intersection Views
  • Minus Views
  • Aggregation
  • Virtual DataPort Functions 

All these operations are explained in the topics “Combination. Foundation”, “Combination. Foundation II”, “Combination. Join”, “Flatten”, “Aggregation” and “Virtual DataPort Functions” included in the official Denodo courses: Data Virtualization Developer Introduction and Data Virtualization Developer Basics.

 

Design Patterns

This section covers top-down design, and to be able to apply this design, Virtual DataPort provides Interface views. Interface views are a special type of view that consists of only a definition of fields and a reference to another view. Therefore, top-down design is where you first define the fields of the interface and then associate the “implementation view” of the interface at a later stage.

How to prepare

The best way to prepare for this section is understand how to create, configure, and implement an Interface view, and to do that, we recommend that the exam taker practices creating, configuring, and implementing different Interface views. The section Creating Interface Views contains all the relevant information.

All the content related to this section is included in the topic “Interfaces. Top-Down Development” in the official Denodo course Data Virtualization Developer Basics.

 

Linking Data and Denodo RESTful Architecture

This section contains questions related to accessing the views created in Virtual DataPort. It includes questions about how to publish REST and SOAP web services, Denodo RESTful Web Services, and clients that can be used to consume the data.

How to prepare

This section can be divided into three sections: 

    1. Publishing web services: This part contains questions about how to publish SOAP and REST Web services. The best way to prepare for this section is to publish and configure a few views and consuming data from these views by calling the created web services.
      1. SOAP Web Service: We recommend creating this type of web service, publishing different views, and calling them using SoapUI. Other important aspects of this type of web service that should be reviewed are the created WSDL, the configuration of input/output fields, and advanced configuration.
      2. RESTful Web Services: The best way to gain practical experience with this is to practice creating RESTful web services, publishing different views, and reviewing how they can be called using the different available formats (HTML, JSON, XML, RSS). Other parts that should be reviewed are how to configure input/output fields, advanced configuration, and URL format.
    2. Denodo RESTful Web Services and Associations: Associations represent relationships between views. Users can navigate through associations using navigation queries or the RESTful web service. The best way to understand associations is to create them and then use navigational queries and the RESTful web service to understand how to navigate between associated views. The RESTful web service of the Denodo Platform is an HTTP service that publishes the contents of the entire Virtual DataPort server. We recommend that you access this web service and review the following:
      1. The types of resources exposed by the RESTful web service
      2. How to invoke the RESTful web service
      3. The URI format of the RESTful web service
      4. HTTP methods and their equivalent VQL statements
    3. Client access to Virtual DataPort: Finally, exam takers should know other ways to access the virtual data layer. The most important ways to execute queries to the Virtual DataPort server are:
      1. Access through JDBC: We recommend that you connect with the Virtual DataPort server using a database tool like DBVisualizer.
      2. Access through ODBC: To test this connection we recommend that you use an ODBC client like WinSQL. 
      3. Web services (as explained above). 

All this information is included in the topics “Data Services. SOAP Web Service,” “Data Services. REST Web Services,” “Linked Data. Associations,” “Denodo RESTful Web Services,” and “Virtual DataPort Clients” in the official course Data Virtualization Developer Basics.

 

Best Practices using the Denodo Platform’s Cache

Virtual DataPort incorporates a system called a “cache module,” which can store a local copy of the data retrieved from data sources in a JDBC database. The questions in this section relate to information about how to configure, load, and perform maintenance on the cache module.

How to prepare

The configuration of the cache database is done in the Server Administration menu; the exam taker should understand:

To understand the cache module, we recommend that you enable the cache and change the configuration, understanding the results in every case.

Information related to the cache database is included in the topics “Virtual DataPort. Cache” and “Virtual DataPort. Cache. Development” in the Advanced Data Virtualization Developer course.

 

Data Lineage and Governance

This section covers the advanced view management and data governance in the Virtual DataPort.

The examinee should have a good knowledge of the following topics:

  • Cache
  • Memory
  • Internationalization Configuration
  • Search Methods
  • Indexes
  • Statistics
  • Execution Plan

The examinee should be aware of all the Denodo tools related to data governance:

  • Tree View
  • Used by
  • Source Refresh
  • Change Impact Analysis
  • Data Lineage

How to prepare

The examinee should have a good knowledge of the following areas of advanced view management and data governance:

We highly recommend that candidates review all the documentation and try changing the configuration to understand the differences between options.

Use of the above tools should be reviewed in the Virtual DataPort Administration tool, to better understand how to use them and when.

All this information is included in the topics “Advanced View Management” and “Virtual DataPort Data Governance” in the Advanced Data Virtualization Developer course.

 

Advanced Optimizer Methods for Improving Denodo Platform Performance

This section contains questions related to the optimization of queries and performance.

How to prepare

To understand performance optimization, examinees should understand the following Virtual DataPort features:

  • Execution Trace
  • Query Delegation
  • Join Strategies
  • Cache
  • Memory Usage

To understand query optimization, examinees should familiarize themselves with the following topics:

Information related to optimization is included in the topics “Performance Optimization” and “Query Optimization” in the Advanced Data Virtualization Developer course.

 

Development Best Practices

This is a practical section related to development best practices.

How to prepare

As well as the official documentation, candidates should review knowledge base articles related to best practices. The article Denodo Admin and Development Best Practices also contains relevant information for this section.

There is additional information included in the topic “Development Best Practices” in the course Advanced Data Virtualization Developer.

 

The Denodo Scheduler

This section is related to the Denodo Scheduler, which enables the scheduling and execution of data extraction and integration jobs, as defined in the different modules of the Denodo Platform.

How to prepare

The examinee should review the following aspects of the Scheduler:

All the information related to the Scheduler is contained in the “Scheduler Administration Guide.” The best way to understand this module is to create different jobs (one of each type), executing queries, and exporting data from these queries.

All the information related to the Scheduler is included in the topics “Scheduler Architecture,” “Scheduler Administration Tool,” “Scheduler Data Sources,” “Scheduler Jobs,” and “Scheduler Job Execution” in the Data Virtualization Developer Basics course.