PHP mysql_connect Vs mysql_pconnect

• Both "mysql_connect" and "mysql_pconnect" are used to connect MySQL database by PHP. Both are having similar function signature.

• Main difference is, if we use "mysql_pconnect", this function would first try to find a persistant link that is already open with the same host, username and password.
• In other words, mysql_pconnect() will try to find a connection that's already open, with the same host, username and password. If one is found, this will be returned instead of opening a new connection

• "mysql_close" function can't close the database object if we connect the database with "mysql_pconnect" method.

• For low traffic websites, its better to use mysql_pconnect method to increase the performance of the website. And for high traffic websites we should use "mysql_connect". Because, in high traffic, lot of database connections will be opened and they will lag the system performance.