If the stack in an Oracle database fails, it can be because the password requirements are not met.
The deployment uses AWS Secrets Manager to randomly generate password for RDS and Informatica domain and services. Oracle RDS has a requirement to start a password with an alphabet character. Sometimes, the randomly generated password may have a number or underscore at the beginning. As there are limited option in AWS Secrets Manager string generator, this issue cannot be avoided. If your choice of database is Oracle, perform the following steps.
Retrieve the RDS password value to check if it is starting with an alphabet.
If the password value does not start with an alphabet, delete the stack and try again.