Good morning,
I understand your nature of problem and demand & I am interested in this job.
I believe you don't want any harm made to the functionality to the existing application in the front end, thus I won't make any changes to the database design, but will try optimizing it's performance applying things within my knowledge, and will ensure you application doesn't lose connection to the database.
As you can see with my profile here, I am an experienced PHP/MySQL application developer with a long track record. Waiting for your kind response.
- Joy