Oracle APPS Interview Questions Part 4

31) What is database driver (D driver) and what does it do?

• It contains all the commands to change the database object.
• All the scripts copied by c driver are applied to the database.
• It makes a list of all the invalid objects that are there in the database.
• Runs SQL scripts which make changes to the database objects.
• Compiles all the invalid objects that are there in the database.

32) What are generate and unified driver and what does they do?

• Generate driver is named as g.drv
• It regenerates all forms, reports and pl/sql libraries that have been affected by the patch.
• Unified driver is a combination of C,D, & G drivers.
• U driver is also named as u.drv
• It requires only a single execution of AutoPatch.

33) Explain about Forms server?

• Forms server is a component of Oracle Applications server which is used to deploy Forms applications across the web.
• It is previously called as Web Forms.
• It consists of Forms Listener, Runtime engine, Forms CGI.
• Forms listener manages connections and Runtime engine.
• Runtime engine contains Application logic, Data management and pl/sql engine.
• It is an optional entry point and used for Load balancing.

34) How to check whether forms server is running or not and how to change the port of the forms server?

• Forms server communicates with forms client and Database server.
• Check for the process f60ctl, if it is running it means the forms are up and running.
• You can find the Forms Server listener's log file at $COMMON_TOP/admin/install/f60srvm.txt.
• You can change the port numbers at f60ctl start by specifying port parameters.
• Modify the file appsweb.cgf which is available at $OA_HTML/bin.

35) Name some of the files related to forms?

Forms files include Script files, Configuration files and text files
• Adfmsctl.sh – It is used for starting and stopping the forms metric client.
• Appsweb.cfg – It is used for defining parameter values used by forms CGI located in $OA_HTML/html/bin.
• Appsbase.html – This is the default HTML file for starting an applet.
• D21c60.txt – this is forms metric client log file.
• D21s60.txt – this is forms metric server log file.

36) What is the difference between socket and servlet mode forms and list some advantages & disadvantages of each?

• In socket mode, we can find a dedicated connection between client desktop and the forms server.
• In servlet mode, Jserv processes the forms requested.
• socket mode uses up to 40% less bandwidth than forms servlet mode.
• Socked mode is not supported on windows-based platforms.
• Servlet connections can be reestablished if network connections drop unexpectedly whereas it is not possible with socket mode.
• Servlet mode HTTP & HTTPS traffic can be easily recognized by routers, whereas socket mode communication is treated as suspect.

37) How do I change from socket to servlet mode and vice versa?

• First, you must login to Oracle Applications Manager
• Then you must navigate to sitemap, then find the Autoconfig.
• In Autoconfig you can able to change from socket mode to servlet mode and vice versa
• Run the autoconfig from backend and restart the forms server.
• Due to many advantages Forms servlet mode is preferred and is always recommended for web deployment.

38) What is JInitiator?

• It is a java virtual machine provided for running web based oracle forms applications inside a client web browser.
• It is implemented as a plug-in or ActiveX Object.
• It allows you to specify the use of Oracle-certified JVM instead of relying on default JVM provided by the browser.
• It is automatically downloaded to a client machine from the application server.
• Its installation and update is performed by standard plug-in mechanism provided by the browser.

39) What is the function of Oracle HTTP (Apache) server?

• Web listener accepts the Http requests coming from the client browsers and web server services the request.
• Apache server forwards advanced processing requests to the servlet engine.
• Servlet engine forwards this requests to database.
• If the Http request needs parsing a JSP file then web listener checks the nature of the request.
• It then contacts the Jserv to run a JSP.
• The JSP contacts the database for the information and returns a HTML page displayed in the web browser.

40) What should I do for debugging when I login to the oracle applications from PHP based applications to avoid hanging?

• First check the Apache log files.
• Then in the Apache log directory, check for the access_log and error_log.
• If you are unable find any information from above steps then check for Jserv logs and JVM.
• Analyze all the errors that you are getting from log files and fix them
• Still you are not able to debug, then perform AOL diagnostics test.