I have a sql database holding some data, and I have a page with bunch of divs (like 30+) displaying this data. Every single div is holding different database value. What i want to achieve is to auto-refresh all that divs with jquery item.load() function so users can see in realtime changes in the database. Is it a good technique or it will really slow down the server if, let's say, 100 users will use this system ?
You need to send minimum calls to server to bring the data for your div to reduce the transport cost for faster refresh. You can send a single call and bring the data and use javascript / jquery to update the divs.
If data being required for refresh is large then you can send more calls to refresh the page so that your GUI starts getting updated before receiving all data. Sending 30 calls for 30 div seems not a good solution.