if i have a webpage with the ability for hundreds of people to login and each upload their own specified document,pdf etc. then be able to see what they uploaded on their profile. how will or can this be done? if the files are uploaded to a directory how can i tell php to know which file belongs to which person by just renaming a file? what if files colide ?
the other thing i was thinking of having these files sent to mysql database and if i did do that what are the chances of the database failing?
Well, it sounds like you have some kind of user authentication in place, so everybody should have a unique username, correcto? If so, then use their username as the naming convention for their files.
If you want to go a step further and see if that particular user has already uploaded a file of the same name and type, use file_exists() and decide at that point if you want to overwrite the file or append something additional to the name.
That way they can upload as many files as they need and they are linked. You could then either left join that table on users.id = files.User_ID or seperately query everything where the files user_id is equal to the users ID.
Also, dont store files in the database like that. It will slow everything down and will be in no way shape or form more efficient.