Type conversion

Hi,

I have find some data type conversion problems with Pgsql (or with me).

1)     Query: select (1::float8 * 1::float8)::text;Result: Fri 31 Dec 22:00:01 1999

2)    Query: select (2000000::int8 * 2000000::int8)::text;Result: ERROR: int8 conversion to int4 is out of range.
Note: I need this conversion to use as argument of function.

3)    Query: select '01/01/1999'::date + '1 month'::timespan;Result OK: 02/01/1999 00:00:00Query: select
'01/01/1999'::date+ '2 month'::timespan;Result not OK: 02/28/1999 23:00:00
 
Note: I think it's using daylight saving (02/13/1999), but for financial uses the result should be: 03/01/1999

4)    Query: select sum(int4_field::int8)::text from table_a;Result: Pgsql don't know how to transform node 107 (or
somethinglike this).
 

5)    Table_a (query 4) has 400,000 rows. Is it normal postmaster allocate 125MB of memory ?

Thanks,

Ricardo Coelho.