12
Wed, Jun
4 New Articles

RPG Academy: Database Modernization - Methodology, Part 8

RPG
Typography
  • Smaller Small Medium Big Bigger
  • Default Helvetica Segoe Georgia Times

Now that you’ve streamlined your database, gotten rid of unnecessary columns and/or tables, and moved all or at least part of the data validation code out of your programs, you’re ready to dive a little deeper into DB2’s advanced functionalities.

The previous TechTips explained how to convert your files’ definitions from DDS to DDL and how to move business validations to the database (or at least, to a separate piece of code, an I/O Server). Now let’s see how you can take advantage of some of DB2’s advanced functionalities. I’ll introduce just two, but there’s a lot to explore, so dig into IBM’s DB2 Reference Manual and find out what goodies you can use in your application’s context.

Step Three: Taking Advantage of DB2’s Advanced Functionalities

IBM has been focusing on DB2 as “the way to move forward” in terms of security and performance, among other things. These are indeed the hottest topics today, so IBM’s choice makes perfect sense, in my opinion. That’s why I’ll talk a bit about those two topics and how you can, with fairly simple changes to your database, achieve interesting results.

Let’s start with security. Before everything was connected to the Internet, data security was often seen as physical security, based on doors, locks, and security guards. Today, data security means something different. It’s not that the physical security has lost its usefulness; it’s just that the threats have changed to become more electronic and less physical. That’s why logical security is so important, based on security levels and encryption. Let’s focus on those two aspects, starting with security levels.

If you’re familiar with IBM i’s authorization model, you know how you can secure your objects from prying eyes and idle fingers. What you might not know is that you can do the same for columns in SQL tables. This is something you simply can’t do in a physical or logical file. Using SQL’s GRANT and REVOKE instructions, you can authorize a user or a group of users differentiated access to specific columns in your tables.

Imagine, for example, that you want user BOSS to be the only one to manipulate the data in the BASE_SALARY column of the EMPLOYEE_MASTER table. You’d start by revoking existing update authorizations, using the following statement:

REVOKE UPDATE(BASE_SALARY) ON EMPLOYEE_MASTER FROM PUBLIC

Then, you’d grant access to the BOSS user, like this:

GRANT UPDATE(BASE_SALARY) ON EMPLOYEE_MASTER TO BOSS

However, users with access to the EMPLOYEE_MASTER table would still be able to see the contents of BASE_SALARY. Therefore, if security was somehow breached, an intruder could see the base salary of the employees. DB2 provides an elegant solution for this type of problem: column-level encryption.

DB2’s Column-Leven Encryption

Starting with V5R3, DB2 includes encryption and decryption column functions so that programmers do not have to write their own encryption routines. Underneath the covers, the DB2 Encrypt and Decrypt scalar functions use the IBM Cryptographic Access Provider 128-bit licensed program (5722-AC3) to add another layer of security around your data. However, there are specific data types and lengths requirements that must be met in order to use the Encryption column function. This is because the encrypted version of the data will be a binary value and longer than the original data string. The data types must be one of the following:

  • BINARY, VARBINARY
  • CHAR FOR BIT DATA, VARCHAR FOR BIT DATA
  • BLOB

For instance, the length of an encrypted string value is the actual string length plus an extra eight bytes (or 16 bytes, if BLOB or different CCSID values are used for the input) and must be rounded to an eight-byte boundary. Up to 32 bytes of hint data can optionally be added and stored with an encrypted value.

Let’s see how the base salary scenario can be solved. During the creation of the table, you’d add a SET ENCRYPTION PASSWORD instruction to the CREATE TABLE:

CREATE TABLE MYAPPDB/EMPLOYEE_MASTER

      ( (some columns here) (…)

      , BASE_SALARY VARCHAR(21) FOR BIT DATA

      , (…) (more columns here) )

      SET ENCRYPTION PASSWORD = <your password here>

      WITH HINT = <your hint here>

Then the insertion of a new record, performed by an I/O server for instance, would look something like this:

INSERT INTO MYAPPDB/EMPLOYEE_MASTER

      VALUES(

            (some columns here) (…)

            , ENCRYPT(<Base salary amount>)

            , (…) (more columns here) )

Now, to see the base salary amount, you need to decrypt it first:

SELECT

      DECRYPT_CHAR(BASE_SALARY, <the password here>)

      , (…) (more columns here)

FROM MYAPPDB/EMPLOYEE_MASTER

As you can see, this is fairly simple to implement, and it’s a good solution when you know your database. It’s true that it can get a bit tiresome when you need to protect multiple columns across several tables, but it’s free, thoroughly tested, and supported by IBM!

Rafael Victoria-Pereira

Rafael Victória-Pereira has more than 20 years of IBM i experience as a programmer, analyst, and manager. Over that period, he has been an active voice in the IBM i community, encouraging and helping programmers transition to ILE and free-format RPG. Rafael has written more than 100 technical articles about topics ranging from interfaces (the topic for his first book, Flexible Input, Dazzling Output with IBM i) to modern RPG and SQL in his popular RPG Academy and SQL 101 series on mcpressonline.com and in his books Evolve Your RPG Coding and SQL for IBM i: A Database Modernization Guide. Rafael writes in an easy-to-read, practical style that is highly popular with his audience of IBM technology professionals.

Rafael is the Deputy IT Director - Infrastructures and Services at the Luis Simões Group in Portugal. His areas of expertise include programming in the IBM i native languages (RPG, CL, and DB2 SQL) and in "modern" programming languages, such as Java, C#, and Python, as well as project management and consultancy.


MC Press books written by Rafael Victória-Pereira available now on the MC Press Bookstore.

Evolve Your RPG Coding: Move from OPM to ILE...and Beyond Evolve Your RPG Coding: Move from OPM to ILE...and Beyond
Transition to modern RPG programming with this step-by-step guide through ILE and free-format RPG, SQL, and modernization techniques.
List Price $79.95

Now On Sale

Flexible Input, Dazzling Output with IBM i Flexible Input, Dazzling Output with IBM i
Uncover easier, more flexible ways to get data into your system, plus some methods for exporting and presenting the vital business data it contains.
List Price $79.95

Now On Sale

SQL for IBM i: A Database Modernization Guide SQL for IBM i: A Database Modernization Guide
Learn how to use SQL’s capabilities to modernize and enhance your IBM i database.
List Price $79.95

Now On Sale

BLOG COMMENTS POWERED BY DISQUS

LATEST COMMENTS

Support MC Press Online

$0.00 Raised:
$

Book Reviews

Resource Center

  • SB Profound WC 5536 Have you been wondering about Node.js? Our free Node.js Webinar Series takes you from total beginner to creating a fully-functional IBM i Node.js business application. You can find Part 1 here. In Part 2 of our free Node.js Webinar Series, Brian May teaches you the different tooling options available for writing code, debugging, and using Git for version control. Brian will briefly discuss the different tools available, and demonstrate his preferred setup for Node development on IBM i or any platform. Attend this webinar to learn:

  • SB Profound WP 5539More than ever, there is a demand for IT to deliver innovation. Your IBM i has been an essential part of your business operations for years. However, your organization may struggle to maintain the current system and implement new projects. The thousands of customers we've worked with and surveyed state that expectations regarding the digital footprint and vision of the company are not aligned with the current IT environment.

  • SB HelpSystems ROBOT Generic IBM announced the E1080 servers using the latest Power10 processor in September 2021. The most powerful processor from IBM to date, Power10 is designed to handle the demands of doing business in today’s high-tech atmosphere, including running cloud applications, supporting big data, and managing AI workloads. But what does Power10 mean for your data center? In this recorded webinar, IBMers Dan Sundt and Dylan Boday join IBM Power Champion Tom Huntington for a discussion on why Power10 technology is the right strategic investment if you run IBM i, AIX, or Linux. In this action-packed hour, Tom will share trends from the IBM i and AIX user communities while Dan and Dylan dive into the tech specs for key hardware, including:

  • Magic MarkTRY the one package that solves all your document design and printing challenges on all your platforms. Produce bar code labels, electronic forms, ad hoc reports, and RFID tags – without programming! MarkMagic is the only document design and print solution that combines report writing, WYSIWYG label and forms design, and conditional printing in one integrated product. Make sure your data survives when catastrophe hits. Request your trial now!  Request Now.

  • SB HelpSystems ROBOT GenericForms of ransomware has been around for over 30 years, and with more and more organizations suffering attacks each year, it continues to endure. What has made ransomware such a durable threat and what is the best way to combat it? In order to prevent ransomware, organizations must first understand how it works.

  • SB HelpSystems ROBOT GenericIT security is a top priority for businesses around the world, but most IBM i pros don’t know where to begin—and most cybersecurity experts don’t know IBM i. In this session, Robin Tatam explores the business impact of lax IBM i security, the top vulnerabilities putting IBM i at risk, and the steps you can take to protect your organization. If you’re looking to avoid unexpected downtime or corrupted data, you don’t want to miss this session.

  • SB HelpSystems ROBOT GenericCan you trust all of your users all of the time? A typical end user receives 16 malicious emails each month, but only 17 percent of these phishing campaigns are reported to IT. Once an attack is underway, most organizations won’t discover the breach until six months later. A staggering amount of damage can occur in that time. Despite these risks, 93 percent of organizations are leaving their IBM i systems vulnerable to cybercrime. In this on-demand webinar, IBM i security experts Robin Tatam and Sandi Moore will reveal:

  • FORTRA Disaster protection is vital to every business. Yet, it often consists of patched together procedures that are prone to error. From automatic backups to data encryption to media management, Robot automates the routine (yet often complex) tasks of iSeries backup and recovery, saving you time and money and making the process safer and more reliable. Automate your backups with the Robot Backup and Recovery Solution. Key features include:

  • FORTRAManaging messages on your IBM i can be more than a full-time job if you have to do it manually. Messages need a response and resources must be monitored—often over multiple systems and across platforms. How can you be sure you won’t miss important system events? Automate your message center with the Robot Message Management Solution. Key features include:

  • FORTRAThe thought of printing, distributing, and storing iSeries reports manually may reduce you to tears. Paper and labor costs associated with report generation can spiral out of control. Mountains of paper threaten to swamp your files. Robot automates report bursting, distribution, bundling, and archiving, and offers secure, selective online report viewing. Manage your reports with the Robot Report Management Solution. Key features include:

  • FORTRAFor over 30 years, Robot has been a leader in systems management for IBM i. With batch job creation and scheduling at its core, the Robot Job Scheduling Solution reduces the opportunity for human error and helps you maintain service levels, automating even the biggest, most complex runbooks. Manage your job schedule with the Robot Job Scheduling Solution. Key features include:

  • LANSA Business users want new applications now. Market and regulatory pressures require faster application updates and delivery into production. Your IBM i developers may be approaching retirement, and you see no sure way to fill their positions with experienced developers. In addition, you may be caught between maintaining your existing applications and the uncertainty of moving to something new.

  • LANSAWhen it comes to creating your business applications, there are hundreds of coding platforms and programming languages to choose from. These options range from very complex traditional programming languages to Low-Code platforms where sometimes no traditional coding experience is needed. Download our whitepaper, The Power of Writing Code in a Low-Code Solution, and:

  • LANSASupply Chain is becoming increasingly complex and unpredictable. From raw materials for manufacturing to food supply chains, the journey from source to production to delivery to consumers is marred with inefficiencies, manual processes, shortages, recalls, counterfeits, and scandals. In this webinar, we discuss how:

  • The MC Resource Centers bring you the widest selection of white papers, trial software, and on-demand webcasts for you to choose from. >> Review the list of White Papers, Trial Software or On-Demand Webcast at the MC Press Resource Center. >> Add the items to yru Cart and complet he checkout process and submit

  • Profound Logic Have you been wondering about Node.js? Our free Node.js Webinar Series takes you from total beginner to creating a fully-functional IBM i Node.js business application.

  • SB Profound WC 5536Join us for this hour-long webcast that will explore:

  • Fortra IT managers hoping to find new IBM i talent are discovering that the pool of experienced RPG programmers and operators or administrators with intimate knowledge of the operating system and the applications that run on it is small. This begs the question: How will you manage the platform that supports such a big part of your business? This guide offers strategies and software suggestions to help you plan IT staffing and resources and smooth the transition after your AS/400 talent retires. Read on to learn: