Oracle regularly releases patches to fix code, security, performance and other vulnerability issues in Oracle Apps. Oracle Support formerly known as Metalink maintains all these information. Metalink is a huge repository of knowledge. You get good reference document and knowledge document. So you may want to check if the patch/fix is applied to your system or not.
How to check that?
Note:- Not all the patch and bug fixes applicable to your system. You should explicitly check with Oracle Support before applying any patch.
In this article, I will share methods to check if patch is applied to your system Before that let see what is bug and patch.
As per Wikipedia,
A software bug is an error, flaw, failure or fault in a computer program or system that causes it to produce an incorrect or unexpected result, or to behave in unintended ways.
A patch is a piece of software designed to update a computer program or its supporting data, to fix or improve it. This includes fixing security vulnerabilities and other bugs, with such patches usually called bug fixes or bug fixes, and improving the usability or performance.
AD_BUGS and AD_APPLIED_PATCHES
ad_bugs and/or ad_applied_patches are metadata tables in Oracle AppsDatabasee. These tables maintain all these information. You may find information about which patch is applied and when is it applied.
ad_bugs – Bug metadata table which stores bug information. You can use below query to get the bug information.
SELECT * FROM ad_bugs;
ad_applied_patches – Patch metadata table to store all patch information applied to the system. You can use below query to get patch information.
SELECT * FROM ad_applied_patches;
Difference between ad_bugs and ad_applied_patches
The difference between ad_bugs and ad_applied_patches is the information it stores. Patch is a collection of bugs. Every bug is having an entry in ad_bugs while there would be only one entry in the ad_applied_patches table.