The CONCATENATE statement, concat() function, and string concatenation operator (&) in QlikView

In QlikView, there is the CONCATENATE statement, the CONCAT() function, and the string concatenation operator (the ampersand – &).  These are all very different and in this post I will explain each of them.


The CONCATENATE statement is used in conjunction with the LOAD statement.  It appends the rows of one table to another.  It is similar to a UNION ALL statement in SQL.

Let’s take a look at a couple examples using the following tables:


Employee_ID Employee_Name Employee_Location
1 John NY
2 Mary NJ


Employee_ID Employee_Name Employee_State
3 Jane FL
4 Evan NY


Employee_ID Employee_Name Employee_Position
5 Paul Cashier
6 Sonia Salesperson

If we concatenated the Employee_Location and Employee_Office tables using the following load script …

 [Employee_ID]       as [%Employee ID],
 [Employee_Name]     as [Employee Name],
 [Employee_Location] as [Employee Location]
 FROM [… data source details for Employee_Location …]

CONCATENATE (Employee_Location)
 [Employee_ID]        as [%Employee ID],
 [Employee_Name]      as [Employee Name],
 [Employee_State]     as [Employee Location]  --aliased column
 FROM [… data source details for Employee_Office …]

We would get this result …


Employee ID Employee Name Employee Location
1 John NY
2 Mary NJ
3 Jane FL
4 Evan NY

Now, if we concatenated the Employee_Location and Employee_Position tables using the following script…

 [Employee_ID]       as [%Employee ID],
 [Employee_Name]     as [Employee Name],
 [Employee_Location] as [Employee Location]
 FROM [… data source details for Employee_Location …]

CONCATENATE (Employee_Information)
 [Employee_ID]        as [%Employee ID],
 [Employee_Name]      as [Employee Name],
 [Employee_Position]  as [Employee Position]
 FROM [… data source details for Employee_Position …]

We would get this result …


Employee ID Employee Name Employee Location Employee Position
1 John NY  
2 Mary NJ  
5 Paul   Cashier
6 Sonia   Salesperson

Notice that the concatenation works even if the tables do not have the same number of columns.  This provide more flexibility than the UNION or UNION ALL statements in SQL where you need to add a dummy column to the select list of your first table before performing the union.

Concat() function

The concat() function concatenates all the values of a column into a single delimited string.  The column and the delimiter are specified as parameters in the function.  You also have the option of producing the result string with only distinct values.

For example, if you have the following table …

Product_ID Product_Description Product_Category
1212 Pen Office Supplies
3214 Paper Paper
1345 Sharpener Office Supplies
1177 Eraser Office Supplies
2780 Calculator Electronics
2901 Computer Electronics
This statement: CONCAT(Product_Category, ‘,’)

Produces: Electronics, Electronics, Office Supplies, Office Supplies, Office Supplies, Paper
Notice there is a space after the comma in the delimiter, and therefore, there is a space after the comma in the output

This statement:   CONCAT(Product_Category, ‘|’)

Produces: Electronics|Electronics|Office Supplies|Office Supplies|Office Supplies|Paper
Notice there is no space in the delimiter, and therefore, no space between the values in the output

This statement:  CONCAT(DISTINCT Product_Category, ‘ | ’)

Produces:             Electronics | Office Supplies | Paper
Notice spaces in the delimiter, and distinct output.

Concatenation operator ( & )

When you need to concatenate 2 strings together, you use the concatenation operator – the ampersand (&).  For example, if you have address values in separate columns as in the table below …

Street City State Zip
123 Main St Orlando FL 32801

… you can output the address as one concatenated string by using the concatenation operator as shown in the script below …

[Street] & ‘, ‘ & [City] & ‘, ‘ & [State] & ‘ ‘ & [Zip]

[Notice a comma and a space is concatenated between Street, City and State; 
and only a space is concatenate between State and Zip]

… and that would produce the following result …
123 Main St, Orlando, FL 32801


Oracle Advanced Security Summary

With the expansion of Self-Service BI, BI Teams need to be more vigilant about protecting sensitive data.
This is a summary of options available for protecting data in Oracle databases.
The information in this post was found here and summarized for a quick read:

The 3 features available are (1) Transparent Data Encryption, (2) Data Redaction, and (3) Data Masking and Subsetting Pack.
Here is a quick summary.

(1) Transparent Data Encryption (TDE)

  • Encrypt data so only authorized people can see it
  • Use it to protect sensitive data that maybe in an unprotected environment, such backup data sent to a storage facility
  • You can encrypt an individual column or an entire tablespace
  • Applications using encrypted data can function just the same

(2) Data Redaction

  • Enable the redaction (masking) of column data in tables
  • Redaction can be full, partial, based on regular expressions, or random
    • Full redaction: replaces strings with a single blank space ‘ ‘; numbers with zero (0); dates with 01-JAN-01
    • Partial redaction: replaces a portion of the column data; for example SSN: ***-**-1234
    • Regular expressions: can be used to perform partial or full redactions
    • Random: generates random values for display when accessed
  • The redaction takes place at runtime; not in the permanent data stored

(3) Oracle Enterprise Manager Data Masking and Subsetting Pack

  • enables you to create a “safe” development or test copy of the production database


Let’s look into some more details …

(1) Transparent Data Encryption (TDE)

  • TDE uses a two-tiered key-based architecture
  • TDE column encryption uses the two-tiered key-based architecture to transparently encrypt and decrypt sensitive table columns. The TDE master encryption key is stored in an external security module, which can be an Oracle software keystore or hardware keystore. This TDE master encryption key encrypts and decrypts the TDE table key, which in turn encrypts and decrypts data in the table column.
  • A Key Management Framework is used for TDE to store and manage keys and credentials.
    • Includes the keystore to store the TDE master encryption keys and the management framework to manage keystore and key operations
    • The Oracle keystore stores a history of retired TDE master encryption keys, which enables you to change them and still be able to decrypt data that was encrypted under an earlier TDE master encryption key.
  • Types of Keystores
    • Software keystores
    • Hardware, or HSM-based, keystores
  • Types of Software Keystores:
    • auto-login software keystores that are local to the computer on which they are created.
    • cannot be opened on any computer other than the one on which they are created.
    • typically used for scenarios where additional security is required while supporting an unattended operation
    • Password-based software keystores
      • protected by using a password that you create. You must open this type of keystore before the keys can be retrieved or used.
    • Auto-login software keystores
      • protected by a system-generated password, and do not need to be explicitly opened; automatically opened when accessed.
      • can be used across different systems; ideal for unattended scenarios.
    • Local auto-login software keystores
  • Steps for configuring a Software Keystore
    • Step 1: Set the Software Keystore Location in the sqlnet.ora File
    • Step 2: Create the Software Keystore
    • Step 3: Open the Software Keystore
    • Step 4: Set the Software TDE Master Encryption Key
    • Step 5: Encrypt Your Data
  • Oracle Database checks the sqlnet.ora file for the directory location of the keystore, whether it is a software keystore or a hardware module security (HSM) keystore.
  • You cannot change an existing tablespace to make it encrypted
  • You can create or modify columns to be encrypted


(2) Data Redaction

  • Define data redaction policies to specify what data needs to be redacted
  • Use policy expressions to set whether a user sees the redacted data or the full data
  • Policy Procedures
  • Sample scrip
    • BEGIN
      object_schema => ‘hr’,
      object_name => ’employees’,
      column_name => ‘commission_pct’,
      policy_name => ‘redact_com_pct’,
      function_type => DBMS_REDACT.PARTIAL, –partial;  use DBMS_REDACT.FULL for full
      function_parameters => DBMS_REDACT.REDACT_US_SSN_F5,  — many standard params, but it can also be custom
      expression =>  ‘SYS_CONTEXT(”SYS_SESSION_ROLES”,”MGR”) = ”FALSE”’); –allows MGR role to see data
      policy_description => ‘Partially redacts 1st 5 digits in SS numbers’,
      column_description => ‘ssn contains Social Security numbers’);
  • Use DBMS_REDACT.ALTER_POLICY and action => DBMS_REDACT.ADD_COLUMN to redact multiple columns
  • Redaction takes place on select lists and not on where clauses
  • Be aware of the scenarios when using redacted tables to build other tables or views


(3) Oracle Enterprise Manager Data Masking and Subsetting Pack (DMSP)

  • DMSP enables you to create a development or test copy of the production database, by taking the data in the production database, masking this data in bulk, and/or creating a subset of the data, and then putting the resulting masked data and/or subset of data in the development or test copy.
  • You can still apply Data Redaction policies to the non-production database, in order to redact columns
  • Used to mask data sets when you want to move the data to development and test environments.
  • Data Redaction is mainly designed for redacting at runtime for production applications


I hope you found this helpful to get you started on taking the steps to protect your data internally and externally.
You can visit the link I provided above to find more details.

DAC Execution Plan Failure – “No active subject areas for execution plan”

When your Oracle Business Intelligence Applications (OBIA) DAC Execution Plan fails with a message that looks like this …

“Retrieving execution plan No active subject areas for execution plan were found

It is likely that you have a missing Subject Area in your Execution Plan in DAC.  You need to attach the Subject Area to the Execution Plan and rebuild the Plan.

After doing this your job should run successfully.


How to generate detailed Oracle BI (OBIEE) Repository Documentation

In this post, I will show the steps for using the OBIEE “Repository Documentation” utility to generate repository (RPD) lineage information.  I will also provide a couple example of how this documentation (output file) can be used.

To access and run the Repository Documentation utility,  from the BI Admin Tool menu, select Tools -> Utilities.


From the Utilities dialog, select “Repository Documentation”, and click “Execute…”


In the “Save As” dialog, select the destination and enter the name you would like for the output file.


When it finishes, it will generate the output csv file.  Note  – this will likely be a large file.  It will contain all your repository objects.


The RPD documentation file will contain the following columns:
Subject Area, Presentation Table, Presentation Column, Description – Presentation Column, Business Model, Derived logical table, Derived logical column, Description – Derived Logical Column, Expression, Logical Table, Logical Column, Description – Logical Column, Logical Table Source, Expression, Initialization Block, Variable, Database, Physical Catalog, Physical Schema, Physical Table, Alias, Physical Column, Description – Physical Column

You can use this file to quickly track lineage from physical sources to the logical columns to the presentation columns and identify all the logic and variables in between.
You can also use it to identify where and how much a specified table, column, variable, etc. is used which will help you to identify dependencies and know the effect of making changes or deleting elements.

Development, Data Governance, and Quality Assurance teams may find this information useful in this format.

The ways of adding data to your Qlik Sense application

This post covers the basics of navigation and selection for getting data into your Qlik Sense application.  More information about each option will be detailed in upcoming posts.

When you are working with a new app to which data has not yet been loaded, with the app open you can use the “Add data” or “Data load editor” icons shown below the app title area to initiate a data load.

Use the “Add data” icon to add data from a file, database, or Qlik DataMarket using the Quick Data Load (QDL) wizard.
Use the “Data load editor” (DLE) to load data from files or databases, and perform data transformation with data load scripts.

If your app already has data, the area below the app title area will contain existing Sheets, Bookmarks, and Stories.  But you will still be able to access the QDL and the DLE.

For the QDL wizard, you can access it from the Global Menu, and select the “Add data” menu item.

For the DLE, you can access it from the Navigation menu, and select the “Data load editor” menu item.

More details about what comes next will be in upcoming posts.

Qlik Sense Desktop Hub Overview

When you start Qlik Sense, it will open to the “hub” page. And you may also see a “Welcome…” dialog window.

qliksensedesktopwelcomedialog From the “Welcome …” window, you may click the “Create a new App” button to start the process of creating a new app, or click the “x” in the top-right to close the window.

Optionally, you may uncheck the “Show this dialog at startup” checkbox before closing it, if you do not want to show this window on each startup of Qlik Sense.  If this was unchecked previously, then this Welcome dialog would not have appeared.

Once you have closed the Welcome dialog, you  will then be in the main hub interface. Let’s take a look at it.


At the top left, you will see the Global Menu. From this menu you can access Help and About, and also access the Dev Hub.  The Global Menu expanded is shown below.


Below the Global Menu is the Apps area.  Here you will see the applications that have been created and saved.

At the bottom of the page, you will see a “Getting started…” button.  Clicking here will bring you to a Qlik Sense support page containing information and resources to help you get started with Qlik Sense.

To the right in the main area of the window, there is a “Create new app” button which you will use when you need to create a new app.

Then, there is an icon for sorting the apps alphabetically – ascending or descending.  Then, another pair of icons for organizing the display of the apps – either in grid format or in list format.

Above that (top-right), you will find the icon for Qlik Cloud, and another icon for Search.

Data Science Fundamentals: Matching

This is a continuation of a series of Data Science Fundamentals posts.  In this post I will briefly describe Matching.

Matching, also known as Similarity Matching, is a technique of using data about objects to identify “like” objects. For example, Amazon or Walmart may use matching to identify “like” customers based on their browsing, liking, and purchasing history.

This information can then be used to provide product recommendations to these customers.


Product recommendations based on browsing and purchase history, and similarity matching

The results of Matching can be used for Classification and Regression; and Matching underlies Clustering.  These techniques were described in previous posts.