APPS INTERVIEW

Cracking The Oracle Apps Dba Interview

1. What happens if the ICM goes down?
2. How will you speed up the patching process?
3. How will you handle an error during patching?
4. Provide a high-level overview of the cloning process and post-clone manual steps.
5. Provide an introduction to AutoConfig. How does AutoConfig know which value from the XML file needs to be put in which file?
6. Can you tell me a few tests you will do to troubleshoot self-service login problems? Which profile options and files will you check?
7. What could be wrong if you are unable to view concurrent manager log and output files?
8. How will you change the location of concurrent manager log and output files?
9. If the user is experiencing performance issues, how will you go about finding the cause?
10. How will you change the apps password?
11. Provide the location of the DBC file and explain its significance and how applications know the name of the DBC file.
Answers
1. All the other managers will keep working. ICM only takes care of the queue control requests, which means starting up and shutting down other concurrent managers.
2.
o You can merge multiple patches.
o You can create a response file for non-interactive patching.
o You can apply patches with options (nocompiledb, nomaintainmrc, nocompilejsp) and run these once after applying all the patches.
3. Look at the log of the failed worker, identify and rectify the error and restart the worker using adctrl utility.
4. Run pre-clone on the source (all tiers), duplicate the DB using RMAN (or restore the DB from a hot or cold backup), copy the file systems and then run post-clone on the target (all tiers).
Manual steps (there can be many more):
o Change all non-site profile option values (RapidClone only changes site-level profile options).
o Modify workflow and concurrent manager tables.
o Change printers.
5. AutoConfig uses a context file to maintain key configuration files. A context file is an XML file in the $APPL_TOP/admin directory and is the centralized repository.
When you run AutoConfig it reads the XML files and creates all the AutoConfig managed configuration files.
For each configuration file maintained by AutoConfig, there exists a template file which determines which values to pick from the XML file.
6.
o Check guest user/password in the DBC file, profile option guest user/password, the DB.
o Check whether apache/jserv is up.
o Run IsItWorking, FND_WEB.PING, aoljtest, etc.
7. Most likely the FNDFS listener is down. Look at the value of OUTFILE_NODE_NAME and LOGFILE_NODE_NAME in the FND_CONCURRENT_REQUESTS table. Look at the FND_NODES table. Look at the FNDFS_ entry in tnsnames.ora.
8. The location of log files is determined by parameter $APPLCSF/$APPLLOG and that of output files by $APPLCSF/$APPLOUT.
9.
o Trace his session (with waits) and use tkprof to analyze the trace file.
o Take a statspack report and analyze it.
o O/s monitoring using top/iostat/sar/vmstat.
o Check for any network bottleneck by using basic tests like ping results.
10.
o Use FNDCPASS to change APPS password.
o Manually modify wdbsvr.app/cgiCMD.dat files.
o Change any DB links pointing from other instances.
11.
o Location: $FND_TOP/secure directory.
o Significance: Points to the DB server amongst other things.
o The application knows the name of the DBC file by using profile option “Applications Database Id.”
Set # 1 : Compatibility
On which databases can Oracle Applications be installed on (i.e. Oracle, SQL Server, Informix, etc.) ?
Answer :-
Oracle database only.
Set # 2 : FND vs. AOL
What is the difference between “FND” and “AOL” ?
What are they ?
What do they mean ?
Answer:-
FND is the system name of core Application Object Library(AOL).
AOL consists of the entire schema which forms the base layer for Functioning of Oracle Applications(without which the Apps can not work).
Set # 3 : Schemas
What is the difference between the following schemas and when are they being
Used by the system :
1) Apps
2) Applsys
3) Applsyspub
Answer :-
Apps is the database schema which used for connecting applications(front end) user It internally uses the Applsyspub user for connecting .It comprises synonyms for all the individual module’s objects. Concurrent Requests also use the apps db schema for executing the requests.
Applsys is a schema in oracle applications which contains the information about the FND or Foundation Tables.
Applsyspub is the schema which used internally in Oracle Applications (Gateway User) by application Users.
Set # 4 : Techstack
What do we mean by Techstack ?
What comprises the Techstack ?
Answer:-
In Oracle Applications the Technical Software Components which comprises of the entire Applications is called Techstack.
They are
1. Db Techstack.—(Database (Oracle RDBMS ) Software.
2. Applications Techstack.(in 11i the 8.06 (i.e. for forms ,reports and for PL/SQL and other libraries) and 8.1.7 for Application Server).(in R12 the releases 10.1.2 and 10.1.3).
Set # 5 : “GL” Database User
When does the system logs in as Database user “gl” and why ?
Answer:-
When using the General Ledger Module Responsibilities the system logs in as Database user gl and this is done for database security.
Set # 6 : Password Change
Before changing password for “apps”, what would you say are the top three
Precautions to be taken (before doing in Production) ?
Can we change the password for user “guest” ? Why ?
Answer:-
Ensure that downtime is taken for changing the apps password.
Ensure that no application users are connected
Ensure that no concurrent requests are running .
And make the application tier down and change the apps user password. This is best approach.
We can change the Guest user’s password. This is done for advanced security.
Set # 7 : “xml” vs. “dbc” files
What’s the difference between the “xml” file and the “dbc” file ? How are they
Being used by the system ?
Answer :-
Xml file in oracle Applications is the context file which is maintained by Autoconfig to maintain the Applications configuration in a centralized manner.
Dbc file is the file used to connect the application user to the database.
Set # 8 : TWO_TASK
What is the “TWO_TASK” variable ? How does Oracle Applications uses it ?
Answer:-
Oracle Applications System maintains TWO_TASK variable for the applications to work properly.
It will be common for database tier and application tier. So that from applications tier users can connect to the database without issues.
Set # 9 : $AD_TOP
What is $AD_TOP ?
What does “AD” stand for ?
Which type of user mostly uses this directory ?
Answer :-
AD_TOP is the TOP for Application DBA Module which contains all the essential utilities and files used for maintaining the Oracle Applications System.
AD stand for Applications DBA.
Application DBA’s mostly use this directory.
Set # 10: Workflows
What is a workflow?
How does Oracle Applications uses workflows?
What would be the top three things to monitor for workflows ?
What would be the top three typical questions to ask about workflows ?
Does a Workflow have a version ? If so, how can we find out ?
Answer :-
Workflow is a module in Oracle Applications .It is also a Standalone Product. Normally workflow is used to carry out the flow of work by approving system and this is mostly used in Order Management.
The top three things to monitor workflow would be.
1.Login as Sysadmin and by using the workflow Administrator web applications monitor for any pending or errored out workflows and correct it.
2.Make sure the “Synch workflow tables” concurrent program is running properly without errors and monitoring the Workflow Managers.
3.Monitor the health of Workflow Notification Mailers .
The Top three typical questions to ask about workflows are.
1.How will you configure a workflow Notification Mailers.
2.How will you navigate and troubleshoot for finding out errored workflow notifications.
3.How will you troubleshoot that if workflow notification mailer is not working properly(not sending e-mails).
Workflow has a Version, by executing the wfver.sql in FND_TOP/sql we can find this component’s version.
How will you find the pending and running concurrent requests from SQL prompt?
after logging as apps user in sqlplus
run this sql $FND_TOP/sql/afrqrun.sql
This will show the pending and running concurrent requests in the instance
Newly Added
What is Transaction Manager(Concurrent Manager) and its purpose?
Ans:-
Transaction Manager is defined so that it has a special pool of database resource to execute concurrent requests.
Its not like other concurrent managers and its not dependent on any concurrent queue tables. i.e when a client submits concurrent request which is assigned to the Transaction Manager then it immediately executes that conc request. This manager is used to run high priority concurrent requests.
How can you restrict application access to only certain users?
Ans :- By editing the apps.conf configuration file in Apache/conf directory and adding the
directive and by giving Allow and bouncing the apache.
Other users will get 403 forbidden error. You can also customize the error message in httpd.conf.
Question :- What are the different options in adpatch and explain about those.
adpatch apply=no
This is done for testing the patch with the instance.This will not apply the patch but generate a logfile which we can check.
adpatch preinstall=y
mostly used in upgrades or specifically when told in a patch readme,This option applies ad updates first then do the rest
nocompiledb
nocompilejsp
nodatabaseportion
nocopyportion
nogenerateportion
nojcopy
nogenform
nolink
adpatch option=hotpatch(for hot mode)–not adivisable for some patches(especially hr global like that)..
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more q&a to come…………………….