Tutor profile: Nathan S.

What is “Shadow IT” and what are some potential benefits and risks?

Shadow IT is the use of systems, platforms, software, and other technologies by those in an organization that circumvent the established review and approval process by IT. Although the use of new technologies and platform can increase productivity and innovation, circumventing controls can potentially have serious security implications such as data exfiltration, malware, and compliance violations.

You’re a mainframe applications developer working on a problem in the Dev/Test environment. There is a bug in a COBOL module that is only used single step of a batch job, and you’ve been tasked to fix it. You have compiled a COBOL module into a personal load library that you believe will fix it as well as a multi-step batch job that you have been using for testing. The JOBLIB card has the load libraries for Dev/Test, UAT, and Production concatenated in its DD statement. Where would you put your personal load library to test your updated module?

You could potentially update the JOBLIB by placing the personal load library at the top of the concatenation as JES will read from the top of the concatenation down to the last library in the JOBLIB DD. A better solution would be to add a STEPLIB DD to the step that uses the module with the load library concatenation in this order: personal load library-> Dev/Test->UAT-Production.

What is an important set of properties for a database management system to have when developing an application that will be executing transactions to ensure against data corruption or data loss?

The ACID model is commonly used for characterizing a transaction when working against a database or multiple databases. A transaction should have a defined unit of work that only succeeds if all operations in the unit of work or executes a rollback if any operation fails (Atomicity), constraints are enforced for each transaction that has been committed (Consistency), concurrency control mechanisms ensure that data is reliable and can prevent exposure to transactions that are uncommitted (Isolation), and permanently change the system if the transaction is successful with a successfully committed transactions being recorded in a persistent transaction log (Durability).