Pailloncy Jean-Gerard <jg@xxxxxxxx> writes: > I do not want for each column and each row to store the value and the > unit. > I do want to put the unit in the definition of the column and the check > on the parser before any execution. If you do that, you foreclose the ability to store mixed values in a single column, in return for what? Saving a couple of bytes per value? (I suppose that in a serious implementation we'd store the units as some sort of reference, not as a string.) Compare the implementation of the NUMERIC type: you *can* constrain a column to have a fixed precision, but you do not *have* to. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org