Q:

Copy input into different cells with jQuery and data-class

Multiple tables contain data in cells.  If I change the data in a cell, they should also be changed in the same cell in other tables. 
<table id="1"><tr><td data-class="row1_col1"><input...></td><td data-class="row1_col2"><input...></td>...<td data-class="rowx_coly"><input...></td></tr></table>

var dataClass   = $(this).data("class");
var dataChk     = this.checked;
$("[data-class]").each(function(){
    if( $(this).attr("data-class") == dataClass){
        do the magic:-)
    }   
});

But these solution is very slowly for big datas. 
Is there a other way like:
$(this).data("class", dataClass ).each(function(){
    do the magic :-)
});

or a other solution? 
Best thanks for helping

A:

$("[data-class='" + dataClass + "']").each(function(){ 
    // Do magic! 
});

DataClass is a variable. 
It works great also with big data sets.