Hi, Gaurang -
Although there are many simple, basic PB questions that can be asked, if it was me in your position, I'd want to ask some questions that would reflect a candidate's ability to successfully maintain MY application. I and others here can probably give you some interview questions (and answers, I suppose ;-)), but first I have a few basic questions for you regarding your PB environment and application:
What version/release of PB are you using? Will you be migrating the app to a newer or latest version?
What version(s) of Windows is being used to host/run the application? Is the app deployed on a Citrix server?
Is the app deployed as a 32-bit app or as a 64-bit app?
Does the app create/send email? Create PDF's (reports)?
Is the application built upon an object framework, such as PowerBuilder Foundation Class (PFC) or Standard Tool & Die (STD)? If not, is there any object inheritance used?
Does the app utilize any Windows API functions or third-party Dynamic-Link Libraries (DLL's)?
Best regards, John