Application of Data Virtualization

DOI : 10.17577/IJERTV10IS020239

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Application of Data Virtualization

Siddhant Garg

School of Computing; DIT University, Dehradun (U.K.); India.

Abstract: In this project, I take different data from different data sources (Eg: PostgreSQL, Excel, Redshift, etc.) and integrate them through Data Virtualization applying tool-Denodo to make a Data Warehouse. It is a simple process to deliver a holistic view of the enterprise.

Key Words: Amazon Simple Storage Service (S3); CSV; Data sources; Data Virtualization; Data Warehouse; JSON; PostgreSQL; XML.


    Data is first and foremost thing in running an IT industry. Data allows companies to more felicitously determine the cause of problems and even find solutions to problems. Good data allows companies to establish criterions, benchmarks, and goals to keep moving forward. Nowadays organizations are facing different issue regarding Big Data but foremost is handling enormous historical data and analyzing to make data useful.

    To overcome these problems, Data Warehouse acts as a central repository of integrated data from a companys operational databases as well as external sources. Data warehouses are merely intended to perform queries and analysis and often contain large proportion of historical data. Its analytical capabilities allow organizations to obtain valuable business insights from their data to improve decision-making.

    The popular techniques for creating Data Warehouse are ETL (Extract, Transform and Load) and Data Virtualization [1]. These are in demand to integrate data from different data sources.

    In todays scenario, the driven data enterprise (Eg: Oracle, IBM) store data in different data sources or servers like pdf, NoSQL, JSON, PostgreSQL, Excel, Cloud and other RDBMS sources. The problem of diversity is – It is difficult to integrate data from different sources and to use it in the system. Data Integration tool perform mapping, transformation, and data cleansing. The diversity is caused when each and every user has a different requirement for these data. According to them, data is stored in different data sources and servers which creates challenge in integrating the different sources of data for a single channel, which is major challenge faced by data driven enterprise (Data Scientist or Data Consumers).


      1. Hardware Requirements:

        • Physical Memory (RAM) of 4GB or more.

        • Graphic card minimum 4GB.

        • Minimum 5GB disk space free.

        • Minimum i5 7th Gen processor.

      2. Software Requirements:

    • Denodo (version 6.0 and above, Express License) [2]

      Limitations of Virtual Data Port with Denodo Express

      Number accounts




      Virtual Data Port includes a default administrator account (admin). As the license only allows you to have one user account, you will always have to use admin.

      Maximum number of simultaneous requests


      Maximum number of rows returned by a query





      Microsoft Access and Excel

      Sources not allowed

      Multidimensional databases: SAP BI, SAP BW, Mondrian, Microsoft Analytical Services and Oracle Essbase.

      Denodo Aracne Google Search Custom wrappers

      The Denodo Browser client cannot be used to retrieve data from CSV, JSON or XML files.

      View parameters

      You cannot set view parameters in a derived view.

      Importing extensions (jars) is not allowed

      This implies not being able to develop custom connectors to sources, custom policies or custom functions.

      Version Control


      Disabled. With Denodo Express you cannot store your work in a Version Control System such as Subversion, GIT, etc.

      JMS listeners cannot be created

      Limitations of Scheduler with Denodo Express

      Maximum number of jobs


    • PostgreSQL (version 12.1)

    • Visual Paradigm (version 16.1)

      Excel (version 16051.12827.20336.0)

    • Excel (csv file) to XML converter

    • Excel (csv file) to JSON converter

    • Amazon Simple Storage Services(S3)

    Limitations for Amazon S3 free usage tier:

    AWS customers receive 5 GB of Amazon S3 Standard storage. 20,000 Get Requests, 2,000 Put Requests, 15GB of data transfer in and 15GB of data transfer out each month for one year.

    • DVD Rental Data


    Tech 1:

    For example, if we take two data sources- (1) Excel file, (2) SQL. In case of integrating data of both the sources, ETL is a needed platform through which data pipelines are created which firstly extracts the data from excel files and ingest them into SQL server.

    Thus, if we apply the same scenario in a data driven enterprise which has diverse data then it is a complex process.

    Tech 2:

    To overcome this challenge, modern technique i.e., Denodo Data Virtualization [3] is used, which works on meta data of the underlying sources of information to develop a single, logical, virtual layer of information and provides them a real-time updated data. This integrates any type of enterprise data siloed which gives a maximum data without any loss or loop – holes. Unlike ETL solutions, which replicate data, Data Virtualization leaves the data in source systems, simply exposed and integrated view of all the data-to-data consumers. Data Virtualization fetches data in real time from underlying source systems and it proves that connecting to data is far superior to collecting it. Currently data storing is not enough to have greater competition, but it is necessary that data should be integrated in a single place so that they cease to be a cost to become business asset. Data virtualization does not normally persist or replicate data from source systems. It only stores metadata for the virtual views and integration logic. Caching can be used to improve performance but, by and large, data virtualization is intended to be very lightweight and agile.


Data Virtualization is a critical part of the Logical Data Warehouse [4] architecture enabling queries to be federated across multiple data sources-(1) traditional structured data sources, such as databases, data warehouses, etc., (2) less traditional data sources, such as Hadoop, NoSQL, Web Services, SaaS applications and so on while still appearing as a single logical data source to the user. It is the ultimate in modern data integration because it breaks down silos and formats, performing data replication and federation in a real-time format, allowing for greater speed and agility and response time. It should be noted that data virtualization is not a data store replicator. Data virtualization does not normally persist or replicate data from source systems. It only stores metadata or the virtual views and integration logic. Caching can be used to improve performance but, by and large, data virtualization is intended to be very lightweight and agile.

I used DVD Rental [5] data which consists of 15 tables and divided them into 5 different data sources i.e., Amazon S3, CSV, PostgreSQL, JSON, XML.

The data source files consisting of different distributed tables are integrated through Denodo and it forms a self-service Logical Data Warehouse.

I analyzed the data by taking some questions:

Q1: What are the top and least rented (in-demand) genres and what are their total sales?

In this, I integrated different tables from different data sources through Denodo and by using Join operator got the result for top and least rented genres and their total sales.


Q2: Who are the top 5 customers per total sales and can we get their detail just in case Rent A Film wants to reward them?

In this, I integrated different tables from different data sources through Denodo and got result for top 5 customers per total sales and their details.

It gives real time data which ETL takes time to process.


It is an excellent solution in compare to ETL as data needs to be accessed and delivered in real- time and this is very important for decision support applications. It also leaves the source data where it is and delegates the queries down to the source systems while ETL copies data from source system and stores it in a duplicate data store.


Data Virtualization is a critical part of the logical Data Warehouse architecture enabling queries to be associated across multiple data sources-traditional structured data sources and less traditional data sources while still appearing as a single logical data source to the user.

The benefits of data virtualization in future for companies are quickly combining different sources of data, improving productivity, accelerating time value, eliminating latency, maintaining data warehouse and reducing the need for multiple copies of data as well as less hardware.


  1. Best+Practices

  2. of_the_denodo_express_license/limitations_of_the_denodo_express_license

  3. [4]

  4. warehouse#:~:text=A%20logical%20data%20warehouse%20(LDW,logical%E2%80%9D%20data%20source%20to%20users.

  5. [5]

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