e-Zest Solutions Software Engineer Java interview questions

I replied to a Chennai based consultancy's mail for the job position. Got a reply in 1 week and the interview was scheduled coming Saturday. Also got regular reminders for the same. The interview process started in time and there were plenty of interviewers available. The recruitment was for 2-10 years experience. The process consists of two technical interviews and an HR interview. I had 2+ years experience. The first technical interview was based on in-depth core Java, higher level understanding of Spring and Hibernate, higher level understanding of databases from business perspective. Some of the questions were : 1) Difference between Oracle and MySQL, MySQL and Postgres, which one to use when and why? 2) Difference between JDBC and Hibernate 3) Tell me in brief about Hibernate 4) Did you work on Hibernate with annotations? (Which I hadn't. I had used the one with XML) 5) Some basic core Java concepts like maps, strings, comparators, etc. 6) Regular expression for decimal point numbers