Oracle Home inventory is corrupted

While running ETCC on Oracle EBS 12.2 we may get following error if Inventory is Corrupted

Error: 
 Oracle Fusion Middleware (FMW) - oracle_common
=======================================================================
Now examining product Oracle Fusion Middleware (FMW) - oracle_common.
Inventory load failed... OPatch cannot load inventory for the given Oracle Home.
Possible causes are:
   Oracle Home dir. path does not exist in Central Inventory
   Oracle Home is a symbolic link
   Oracle Home inventory is corrupted
LsInventorySession failed: OracleHomeInventory gets null oracleHomeInfo

Cannot confirm bugfixes applied to /u02/ebsappl/PTEST1/fs1/FMW_Home/oracle_common

Inventory could not be checked. Error code: 73.


Exiting.

Solution:

[appltest@test u02]$ cd /u02/ebsappl/PTEST1/fs1/FMW_Home/oracle_common/oui/bin

[appltest@test bin]$ ./attachHome.sh

Starting Oracle Universal Installer...

Checking swap space: must be greater than 500 MB.   Actual 63999 MB    Passed

Preparing to launch Oracle Universal Installer from /tmp/OraInstall2019-02-21_03-46-38PM. Please wait ...[appltest@test bin]$ The inventory pointer is located at /etc/oraInst.loc

The inventory is located at /u01/oraInventory

'AttachHome' was successful.

How to know the Database Size

We can know the DB size by following queries:

Which version of TXK Delta patch

How can we know Which version of TXK Delta patch we have currently ?

To find which version of ADc Delta and TXKc Delta patches we have query with the following command..

SELECT codelevel FROM AD_TRACKABLE_ENTITIES WHERE abbreviation in ('txk','ad');

In the above screenshot the version of TXK and AD are Delta 8