Composite keys, large result sets, interactive scrolling

Suppose a table with columns: col1 col2 col3 col4 col5 col6 ... where these columns by the definition of the table, are not allowed to contain NULL. A composite key key_comp is made of number of these columns: key_comp = (col3,col4,col1,col2,col7) Suppose the cols are all character, the logical composed key would be the concatenation of the columns. Can Informix handle the queries (written in pseudo-sql): select * from table where key_comp > (?,?,?,?,?) or select * from table where key_comp <= (?,?,?,?,?) or select * from table where key_comp >= (?,?,?,?,?) or select * from table where key_comp < (?,?,?,?,?) where the result set is "big" f.ex. 3 million rows of a table with 6 million rows and the user wants to scroll through the set (page by page, f.ex. 20 lines) and have an optimal answer time (that fills without delay the screen). How has the query to be written in Informix to achieve it? Bernard Dhooghe