Infinity and NaN should not escape from the engine. Client side tools should not see the special values. Integer overflow should be detected in the server side, too.

SQL> select 1e161/1e-161from rdb$database;

                 DIVIDE
=======================
Statement failed, SQLSTATE = 22003
arithmetic exception, numeric overflow, or string truncation
-Floating-point overflow. The exponent of a floating-point operation is greater than the magnitude
allowed.

This is correct detection.

SQL> set sql dialect 1;
WARNING: Client SQL dialect has been set to 1 when connecting to Database SQL dialect 3 database.
SQL> select 1e161/1e-161from rdb$database;

                 DIVIDE
=======================
               Infinity

AFAIK, dialect 1 should be protected as well. Multiplication is protected in both dialects.

We need to protect sum and subtraction as well:

SQL> set sql dialect 3;

SQL> select 1e308 + 1e308 from rdb$database;

                    ADD
=======================
               Infinity

SQL> select 1e308 - -1e308 from rdb$database;

               SUBTRACT
=======================
               Infinity