> How to make sure the K keys fit in a page? It is called ARITHMETIC. You know the amount of "space" on a page that can contain data, and you know the size of a key and the size of a pointer. Therefore the application of rudimentary grade school arithmetic will allow you to compute the maximum number of keys K that can be stored in the available space. Or was that a "trick question" of some sort? > Also what are the keys metioned in fileformat.html and the keys in the sense of SQL language? ``` create table t ( c0, c1, c2, c3 ... primary key ( key_column_list ), unique ( key_column_list ) ); create index i on t ( key_column_list ); ``` Is that another trick question?