Oracle Apps DBA Interview Questions

Q. I am applying a patch , can I open another session and run adadmin?
Yes, We can run unless you are running a process where workers are involved

Q. I am applying a patch , can I open another session in another node and run adpatch?
No because it will create tables while running first session when you start the 2nd session it will fail due to the first

Q. How to determine Oracle Apps 11i Version?
select RELEASE_NAME from fnd_product_groups;
You should see output like

Q. How to find Database version?
SQL> select * from v$version;
The command returns the release information, such as the following:Oracle9i Enterprise Edition Release – ProductionPL/SQL Release – ProductionCORE ProductionTNS for 32-bit Windows: Version – ProductionNLSRTL Version – Production

Q. How to find opatch Version?
opatch is utility to apply database patch , In order to find opatch version execute”$ORACLE_HOME/OPatch/opatch version”
You can check OPatch -lsinventory

Q. How to find out invalid objects in the database
select count(*) from dba_objects where status =’INVALID’

Q. How you will see hidden files in linux/solaris?
ls -la

Q. How to find that the database is 64-bit/32-bit?
$RDBMS_ORACLE_HOME/bin/file oracle

Q. What is top command?
top is a operating system command, it will display top 10 processes which are taking high cpu and memory. 8. What is a patch?A patch can be a solution for a bug/it can be a new feature.

Q. What are the different types of patches?
oneoff, mini packs, family packs, maintanance packs, rollup pathches, colsolidated patches.

Q. What is a oneoff patch?
An oneoff patch is a small patch of (20-90K size) without any pre-req’s

Q. What is a mini pack?
A mini pack is one which will upgrade any product patchset level to next level like AD.H to AD.I

Q. What is Family pack?
A Family pack is one which will upgade the patchset level of all the products in that family to perticular patchsetlevel.

Q. What is Maintanance pack?
A maintanance pack will upgrade applications from one version to another like 11.5.8 to 11.5.9

Q. What is a Rollup patch?
A rollup patch is one which will deliver bug fixes identified after the release of any major application versions like 11.5.8/11.5.9

Q. What is consilidated patch?
Consolidated patches will come into pictures after upgrades from one version of applications to anoter, all post upgrade patches will a consolidated and given as consolidated patch.

Q. How u will find whether a patch is applied/not?
Query ad_bugs.

Q. What is the other table where u can query what are the patches applied?

Q. What is the difference between ad_bugs and ad_applied_patches?
A patch can deliver solution for more than one bug, so ad_applied_patches may not give u the perfect information as in case of ad_bugs.

Q. How u apply a patch?

Q. What inputs you need to apply a patch other than driver name and etc?
apps and system passwords

Q. What are the table u r adpatch will create and when?
Adpatch will create FND_INSTALL_PROCESSES and AD_DEFERRED_JOBS table when it will apply d,g and u drivers

Q. What is the significance of FND_INSTALL_PROCESSES and AD_DEFERRED_JOBS table?
FND_INSTALL_PROCESSES table will store the worker information like what job is assigned to which worker and its status. AD_DEFERRED_JOBS will come into picture when some worker is failed, it will be moved to AD_DEFERRED_JOBS table, from where again adpatch will take that job and try to resign, after doing this 3 times if still that worker is failing, then adpatch will stop patching and throw the error that perticular worker has failed. We need to trouble shoot and restrart the worker.

Q. If it is a multinode installation which driver we need to apply on which node?
c,d,g on concurrent node and c, g on web node. If it is u-driver we need to apply on all nodes.

Q. While applying a application patch is that necessary that u r database and listener should be up?
Yes . why because adpatch will connect to database and update so many tables etc…..

Q. While applying a patch if that patch is failing because of a pre-req then how you will apply that pre-req patch and resume with the current patch?
We need to take the backup of FND_INSTALL_PROCESSES and AD_DEFERRED_JOBS tables and restart directory at APPL_TOP/amdin/SID and then use adctrl to quit all the workers. Then apply the pre-req patch , after that rename u r restart directory to its original name and create FND_INSTALL_PROCESSES and AD_DEFERRED_JOBS tables from the bcakup tables. Start adpatch session and take the options want to continue previous session.

Q. What is adctrl?
Adctrl is one of the adutilities, which is used to check the status of workers and to manage the workers.

Q. Can u name some of the menu options in adctrl?
Check the status of workers, tell manager that worker has quited, restart a failed worker etc….

Q. How to skip a worker and why?
We can skip a worker using option 8 in adctrl which is hidden. We will go for skipping a worker when we have executed the job which the worker is supposed to do.

Q. How adpatch knows what are the pre-req’s for the patch which it is applying?
With every patch a file called b.ldt file will be delivered which contain the pre-req information. adpatch load this into databse using FNDLOAD and check , whether those pre-req patches were applied or not.

Q. What is FNDLOAD ?
FNDLOAD is a utility which is similar to sqlloder but loads code objects into database, where as SQLLOADER loads data objects into database.

Q. What c-driver will do?
C-drive copies the files from patch unzipped directory to required location in u r application file system. Before copying it will check the file version of the existing file at the file system with the file version of the file in the patch. If the patch file version is higher than what it is at file system level then only c-driver will copy that files.

Q. How adpatch will know the file versions of the patch delivered files?
With each patch a file with name f.ldt is delivered , which contain the file versions of the files dilivered with the patch. Adpatch will use this file to compare the file versions of files its delivering with the file on file system.

Q. What is the adpatch log file location?

Q. What is the worker log file name and its location?
adwork01,adwork02…… and location is APPL_TOP/admin/SID/log

Q. How u will know what are the files the patch is going to change just my unzipping the patch?
When u unzip a patch it will keep all the files related to a particular product under that directory inside u r patch directory for example if the patch delivering files related to FND product then it will create a sub directory under the patch directory with the name FND in which it will put all related files to that product

Q. What is the significance of backup directory under u r patch directory?
When we apply a patch it will keep the copy of the files which its going to change in file system.

Q. What are the different modes you can run your adpatch?
1. Interactive – default mode
2. Non interactive – Use defaults files to store prompt values
(adpatch defaultsfile= interactive=no)
3. Test – Without actually applying a patch just to check what doing.(adpatch apply=no)

Q. How u will monitor u r applications as well as database?
We have our custom scripts which is sheduled to run at a specific time which will monitor whether applications and databases are up/not. And it will mail us if some processes is not running. And we have one script which will check database alert log for ORA errors and mails it to us . Based on this we will react.

Q. What are the latest ORA errors u have encountered?
Useually we will get the ORA errors like unable to extend the tablespace by so and so size. And we will check those tablespaces for space, if space is not there we will resize the datafile and add one more datafile.

Q. Which table u will query to check the tablespace space issues?
bytes column in dba_free_spaces and dba_data_files

Q. Which table u will query to check the temp tablespace space issues?

Q. What is temp tablespace? And what is the size of temp tablespace in u r instances?
Temp tablespace is used by so many application programs for sorting and other stuff. Its size is between 3 to 10 GB.

Q. What is autoconfig?
Autoconfig is an adutility which is used to maintain application environment and configuration files.

Q. What are the parameter autoconfig will ask for?
Context file name and apps password

Q. What is context file?
Context file is a central repositary, which stores all application configuration information. The name is like _ .xml

Q. How you will find autoconfig is enabled/not for u r applications?
Open any env / configuration files, the first few lines will tell u that this files are maintained by autoconfig.2. Ifcontextname.xmlfile is there in APPL_TOP/admin

Q. How autoconfig will create env and configuration files?
Autoconfig will go to each and every top template directory take the templates from there and fill the values from xml file and create the required files.

Q. In how many phases autoconfig will run?
Autoconfig will run in 3 phases.
1. INIT – Instantiate the drivers and templates
2. SETUP – Fill the templated with values from xml and create files
3. PROFILE – Update the profile values in database.

Q. What is the location of adconfig log file?

Q. Is it possiable to restore a autoconfig run?
Adconfig will create a script at $APPL_TOP/admin//out/. This will copy the backed up files before autoconfig run to its original locations. But the profile values updated in the database can’t be restored back.

Q. How to run autoconfig in test mode? script at AD_TOP/bin. This script will run autoconfig in test mode and create the difference file which tells us what is going to change , when u actually run autoconfig.

Q. How to find autoconfig is enabled or not for database?
If we have appsutil directory under RDBMS_ORACLE_HOME


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