SET SQLDA_DISPLAY
Firebird 2.0
SET SQLDA_DISPLAY [ON | OFF]
This is a hidden command which is not mentioned in the output from the help set command.It displays internal details about the SQL statements being executed by isql.
SQL> set sqlda_display on;
SQL> select count(*) from employee;
INPUT message field count: 0
OUTPUT message field count: 1
01: sqltype: 580 INT64 scale: 0 subtype: 0 len: 8
  :  name: COUNT  alias: COUNT
  : table:   owner:
                COUNT
=====================
                   42