I am already an OCA PL/SQL Certified associate. Now I'm planning to give the 1Z0-147 SQL Database Certified expert exam by end of this month.
I find in the site that this Certified exam is independent of OCA/OCP/OCM exam.
The Oracle SQL Expert exam is 1Z0-047. The exam 1Z0-147 is "Program with PL/SQL".
That aside, Expert exams are completely independent of OCA/OCP exams. If you pass 1Z0-047, you will gain the SQL Expert certification. If you are interested, you can find links to study materials for the exam here:
Do you have any other spl suggestions / advice about this exam?
Don't expect it to be a pushover. OCE exams are much more difficult than OCA exams. This one gets failed a lot because people who have passed the SQL Fundamentals exam think that the SQL Expert exam is going to be about the same. It isn't.