Delphi programming

General information for the business: windows desktop application and php online system
Description of requirements/functionality: I have a desktop Epos system developed with Delphi7 and Online ordering system developed with php and mysql.
Both systems are completely different and isolated, I have developed a delphi program which query the mysql database every minute for any new orders to be downloaded and printed, this is been working fine so far, my concern that now I have over 450 online systems and if you can imagine over 450 desktop application querying the database every minute and creating all of these connections it's putting a lot of load on mysql server.


I need someone with some good experience in this field to help me to come up with a better way of pulling the data from mysql database without overloading the server.
OS requirements: Windows
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