PTC Software Engineer interview questions

I am currently an intern at PTC and interviewed for another team. The hiring manager contacted my manager who contacted me. I had three people interview me, the team manager and two senior team members. Two were in the room with me while one was on the phone in a conference call with us. During the interview, the two technical questions were: follow a stack trace and what do these SQL statements do, and what could you do to improve the performance.