ORA-00059: maximum number of DB_FILES exceeded

This parameter is in the CONTROL FILE,but you do not need to recreate control file. See below:

$sqlplus /nolog
conn / as sysdba

SQL> show parameter db_files;
NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
db_files                             integer     200

SQL> alter system set db_files=250 scope=spfile;
System altered.

SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup
ORACLE instance started.

Total System Global Area  268435456 bytes
Fixed Size                  1218892 bytes
Variable Size              75499188 bytes
Database Buffers          188743680 bytes
Redo Buffers                2973696 bytes
Database mounted.
Database opened.

SQL>show parameter db_files
NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
db_files                             integer     250
SQL> exit

OAuth and OpenID Userful Video Resource

OAuth
http://www.youtube.com/watch?v=PqNjmMvpeT4

OAuth Presentation
http://www.youtube.com/watch?v=S8zmDIlGsV8

Securing Rest-ful Web Services with OAuth2
http://www.youtube.com/watch?v=8uBcpsIEz2I

Cloud Foundry Blog
http://blog.cloudfoundry.org/2012/10/09/oauth-rest

Authentication OAuth 2.0
You're building an API and the question comes up, how to let client applications authenticate against it? Giving username/password to 3rd party client applications is a security anti-pattern. You don't want to do that. API keys are better, but confusing for the average user. So we're going to look at solving that with OAuth 2.0.
http://www.youtube.com/watch?v=khnmMv4_RCE

Google I/O 2012 - OAuth 2.0 for Identity and Data Access
http://www.youtube.com/watch?v=YLHyeSuBspI
This session will cover the latest advances in how OAuth can be used for data access, but will also dive into how you can lower the barrier to entry for your application by allowing users to login using their Google accounts. You will learn, through an example written in Python, how to use OAuth 2.0 to incorporate user identity into your web application. Best practices for desktop applications, mobile applications and server-to-server use cases will also be discussed.

OAuth and OpenID for Data Access and Identity in web apps
http://www.youtube.com/watch?v=U9Dfr_VIpic

OAuth 2.0 Tutorial 3 Implicit Grant Type Using Layer 7 OAuth Toolkit
http://www.youtube.com/watch?v=OfgVewoEbX0&list=PL032A5954701D543C

Facebook Google Login OAuth
http://www.youtube.com/watch?v=Q8s8AyL71Uk

Google OAuth Demo: Step #1 Initial Preparations
http://www.youtube.com/watch?v=_uLB_vn0et0

Authentication with OAuth and Connected Apps
http://www.youtube.com/watch?v=SBeO-Jkx3LA

OAuth 2.0 - Part 4
http://www.youtube.com/watch?v=0PvQcLzVGF0

OAuth 2.0 in Depth.mp4
http://www.youtube.com/watch?v=hEewiXlynyc

Oracle API Gateway Installation and Configuration

Overview:

Oracle API Gateway is a comprehensive platform for managing, delivering, and securing Web APIs. It provides integration, acceleration, governance, and security for API and SOA-based systems. Oracle API Gateway is available on Windows, Linux, and Solaris (for more details, see the Oracle API Gateway Installation and Configuration Guide).

Purpose: 

This document will cover the installation part of the Oracle API Gateway 11gR2PS1.Use the below hyperlink to download the Oracle API Gateway Download.  

Installation:

• Extract the zipped file to the appropriate location.
• Run the executable file "OAG-11.1.2.1.0-linux-x64-installer.run"
• Follow the instructions as per the below screen shots.

Click Next to continue.(Omit)

URL: https://<hostname>:8090/

username: admin

Password: changeme

Below are the few screen shots of API gateway home page and Policy store consoles.

 

Starting the Policy Studio
If you did not select to launch the Policy Studio after installation, perform the following steps:
    1.Open a command prompt.
    2.Change to your Policy Studio installation directory
      (for example, INSTALL_DIR\oagpolicystudio).
    3.Start policystudio.

For details, you can refer to following url:
http://docs.oracle.com/cd/E39820_01/doc.11121/gateway_install_docs/content/install_gateway.html