> -Max number of columns in a select statement

I think the limit is the same as for table, i.e. select as many columns
as you wish, but you can't exceed total width 64K.

E.g. you can't do
CREATE TABLE tab (x VARCHAR(20000));
SELECT x,x,x,x FROM tab;

> -Max length of a statment.

There are many different limits, none of which is properly documented.
E.g. max. length of SQL string, max. length of generated BLR,
max. number of Joins, max. number of AND/OR operators, etc.

> -Max number of columns in the order by clausule

The documented limit is
"Maximum size of key in sort clause = 32K"

(But FB server complains at 64K)


Ivan
http://www.volny.cz/iprenosil/interbase