Ext JS 4's brand new grid supports infinite scrolling, which enables you to load any number of records into a grid without paging.
The new grid uses a virtualized scrolling system to handle potentially infinite data sets without any impact on client side performance.
The code is not minified, see infinite-scroll.js
The grid's viewSize is configured as 50 which means that only 50 data rows are rendered at any time.
As the edge of the rendered data scrolls towards being in view, the table is refreshed, and repositioned to maintain
visual scroll position.