way(client side or server side) to go for pagination /sortable columns?

Question

I have 3000 records in an employee table which I have fetched from my database with a single query. I can show 20 records per page. So there will be 150 pages for with each page

Answer 1

Sending data to your client is almost certainly going to your bottleneck (especially for mobile clients), so you should always strive to send as little data as possible. With that said, it is almost definitely better to do your pagination on the server side. This is a much more scalable solution. It is likely that the amount of data will grow, so it's a safer bet for the future to just do the pagination on the server.

Also, remember that it is fairly unlikely that any user will actually bother looking through hundreds of result pages, so transferring all the data is likely wasteful as well. This may be a relevant read for you.