Hi,

There are many PHP scripts available from the open source community and retail market. Some spec out the requirements and specifications in very details but unfortunately some don't.

So, my question is How can I be sure the script I'm going to use can support a big traffic site? Often I heard many scripts are written and optimize for small traffic websites in mind and they will start to behave strangely if the traffic started to grow.

Can I learn this by looking at the PHP codes itself? or perhaps see the database structure in some way to answer my question.

I'd appreciate if you can share your comments and ideas on this. Thank you so much.

Cheers,

So, my question is How can I be sure the script I'm going to use can support a big traffic site?

By testing it, simply.
There are tools for that, like "ab" (apache benchmark) where you can specify how many users, how many concurrent connections, and for how long the app should generate as traffic.
Once you fired this application, take a look on the server stats.
"jmeter" is another app to do that:
http://jakarta.apache.org/jmeter/
The advantage of jakarta is that it can graph the server response time for you.

Can I learn this by looking at the PHP codes itself? or perhaps see the database structure in some way to answer my question.

Only if you are a good enough programmer to understand every every possible behaviour of the code under ALL load conditions.

Finding some high traffic sites that use the same scripts might be logical start and give you some clues.