Oracle Apps DBA - Patching

1. What is a patch?
Ans: A patch can be a solution for a bug/it can be a new feature.

2. What are the different types of patches?
Ans: one-off, mini packs, family packs, maintenance packs, rollup patches,
consolidated patches.

3. What is a one-off patch?
Ans: An one-off patch is a small patch of (20-90K size) without any pre-req’s

4. What is a mini pack?
Ans: A mini pack is one which will upgrade any product patch set level to next
level like AD.H to AD.I

5. What is Family pack?
Ans: A Family pack is one which will upgrade the patch set level of all the
products in that family to particular patchsetlevel.

6. What is Maintenance pack ?
Ans: A maintenance pack will upgrade applications from one version to another
like 11.5.8 to 11.5.9

7. What is a Rollup patch?
Ans: 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

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

9. How u will find whether a patch is applied/not?
Ans: Query ad_bugs.

10. What is the other table where u can query what are the patches applied?
Ans: Ad_applied_patches.

11. What is the difference between ad_bugs and ad_applied_patches?
Ans: 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.

12. How u apply a patch?
Ans: ad patch

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

14. What are the table u r ad patch will create and when?
Ans: Ad patch will create FND_INSTALL_PROCESSES and
AD_DEFERRED_JOBS table when it will apply d, g and u drivers

15. What is the significance of FND_INSTALL_PROCESSES and
AD_DEFERRED_JOBS table?
Ans: 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 particular worker has failed. We need to trouble shoot and restart the worker.

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

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

18. 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?
Ans: 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
backup tables. Start adpatch session and take the options want to continue
previous session.

19. What is adctrl?
Ans: Adctrl is one of the ad utilities, which is used to check the status of workers and to manage the workers.

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

21. How to skip a worker and why?
Ans: 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.

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

23. What is FNDLOAD?
Ans: FNDLOAD is a utility which is similar to sql-loader but loads code objects
into database, where as SQLLOADER loads data objects into database.
 
24. What c-driver will do?
Ans: 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.
 
25. How adpatch will know the file versions of the patch delivered files?
Ans: With each patch a file with name f.ldt is delivered, which
contain the file versions of the files delivered with the patch. Adpatch will use this file to compare the file versions of files it’s delivering with the file on file system.
 
26. What is the adpatch log file location?
Ans: APPL_TOP/admin/SID/log
 
27. What are the worker log file name and its location?
Ans: adwork01, adwork02…… and location is APPL_TOP/admin/SID/log
 
28. How u will know what are the files the patch is going to change just my
unzipping the patch?
Ans: 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
 
29. What is the significance of backup directory under u r patch directory?
Ans: When we apply a patch it will keep the copy of the files which its going to
change in file system.
 
30. What are the different modes you can run your adpatch?
Ans: 1.Interactive – default mode
2. Non interactive – Use defaults files to store prompt values
(Adpatch defaults file= interactive=no)
3. Test – Without actually applying a patch just to check what its
doing.(adpatch apply=no)
4. Pre-install – (adpatch preinstall=y) this mode will be useful to decrease
upgrade downtime as it applies bug fixes without running SQL, EXEC and
generate portion of patch.
 
31. How u will monitor u r applications as well as database?
Ans: We have our custom scripts which are scheduled 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. 

32. When a patch delivers java files what extra file u will get when u unzip the
patch, other then u r driver and read me files?
Ans: j.zip
 
33. What is apps.zip/appsbrog2.zip file?
Ans: apps.zip/appsbrog2.zip is the patchable archive of all java class files
required for oracle application.
Apps.zip was used to old application version, but from 11.5.8 onwards its
appsbrog2.zip
 
34. What is the location of apps.zip/appsbrog2.zip?
Ans: AU_TOP/java and JAVA_TOP

35. How to skip copy portion while applying a patch?
Ans: Adpatch options=nocopyportion
 
36. How to merge patches and what type of patches can be merged?
Ans: admrgpch. We can merge any kind of application patches, if any of the
patch contain a u-driver then merged patch will contain u_merged.drv otherwise c_merged.drv, d_merged.drv and g_merged.drv