Hello there!

I am considering to use PHP to write the client software for an application that has to manage the inventory of a company, its purchases, its sales, the the movements of items between branches, etc.
Now I have to doubts:
1- I know PHP is great for websites that needs access to a small DB, but... is PHP good enough to develop the app I want?
2- PHP is great if there are few interactions with the DB and thus few windows must be generated, but... if the app has to continuously interact with the DB and new windows need to be generated every few seconds, will the user note the acumulated latency? (I you access a web page where you have to provide some data and go through 3 pages to do what you want, it does not matter if there is a little latency. But if you are hours and hours in fornt of an app. even the samllest latency can be a problem, I think)

Thanks