A data sketch is a class of algorithms that all sort of like use roughly fixed width in binary, usually representations. And then in a single pass so their o n will look at each row and hash the row and then update the sketch object essentially. Those sketch objects also have another property that they are mergeable. So you can map, reduce it in, you know, trivial speeds. The net result is that this like tight binary packed object can be used to approximate measures on the original data.