2009/12/19 Andrus <kobruleht2(at)hot(dot)ee>:
>
> set transaction isolation level read uncommitted;
the "isolation level" is for specifying what rows are visible no for columns.
besides, postgres doesn't implement "read uncommitted"
> update test1 set a=4, b=a ;
>
> b value is 1 but must be 4.
no. b value "must be" 1, you want it to be 4...
in an update the columns always hold the old value until the statement
is finished, the only way i can think for doing this is with a trigger
--
Atentamente,
Jaime Casanova
Soporte y capacitación de PostgreSQL
Asesoría y desarrollo de sistemas
Guayaquil - Ecuador
Cel. +59387171157