>>"Paolo Saudin" <pa...@ecometer.it> writes: >> I have a problem with a query wich simple aggregate values. In the sample >> below I have two values, 1.3 and 1.4. Rounding their average with one >> decimals, should give 1.4. > >You seem way overoptimistic about float4 values being exact. They are >not. The actual computation being done here is more like > >regression=# select (1.3::real + 1.4::real) / 2 ; > ?column? >------------------ > 1.34999990463257 > (1 row) > >If you want an exact sum with no roundoff error you should be storing >all your values as numeric (and taking the consequent speed and space >hit :-(). > > regards, tom lane >
I converted all the fields in numeric type instead of real and now both queries return the same result ! Now I need to test about performances ... Thank you very much !! Paolo Saudin -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
