> Also, it's possible your initial selection is slow. I imagine having tbody > in there isn't helping at all, and is probably making it slower. "#tableId > tr" or even better, "#tableId > tbody > tr" would probably be faster.
The shorter the selector, the faster it is and every time you see a space, >, +, or ~ in your selector - double how long it takes (a very rough rule of thumb). "tr" is faster than "#table tr" is faster than "#table tbody tr" is faster than "#table > tbody > tr". Of course, all those selectors actually select different things, therefore your mileage may vary. --John
