Is there anyway to run apex on application server while having database on another server. I meant to say that I want to make one database server in which oracle database will be installed and another application server on that apex will be installed? Is there any possible way to do that?
I've tried it by connect through remote database and it is working but I had to install oracle database on both server.
NO. APEX is a set of PL/SQL and SQL code that MUST execute in the Oracle database. You could run a smaller DB on the app server to host APEX apps and host the customer data tables on a different server. But APEX must run in an Oracle DB. Period.